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Discussion Starter · #1 ·
Shopping for lifter, rod, and rocker arm replacements for my 83-84 L69 305 H.O.

Which 1976-1988 305 engines had a roller cam from the factory, and can I visually tell if the lifters are flat or roller by simply looking at the rocker arms ?

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Can't tell by looking at the rocker arms....but you can easily tell by looking into the lifter valley.
There will be a spring steel sheetmetal "spider" and paired "dogbone" alignment bars in each pair of lifters.

L-69 engine was never roller cam....only the TPI fuel injected engines in the Z28 and IROC Camaro / Trans Am and Formula Firebird or the Corvette got roller cams in those years.....1986-up.

Spider and dogbones are in this picture....the third piece is the camshaft thrust retainer. Each pair of lifters will have a dogbone holding the top of the lifters, while the spider holds the dogbones down.
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Putting new flat tappet lifters on a used cam will frequently wipe out cam lobes and force you to rebuild the engine.

Why do you think you need to replace the lifters, pushrods, and rocker arms??
 

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Also, keep in mind that a good, low-mileage, used 305 or 350 is likely $300 at the junkyard. I totally get it if you want to do the work, but if it's cost that's important, $300 and about 5 hours gets you a good factory assembly, possibly even an ujpgrade.

As Ericnova said, not ever a good idea to put new flat lifters on an old cam (or vice versa). Very good chance it will wipe a lobe and/or lifter in very short order. You'll need a cam as well if it's flat tappet... which is almost certainly is.

Help us help you out by letting us know why you need pushrods, rockers, and lifters.
 

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If it has a factory roller cam you can see this with a rocker cover removed. First is look for self guiding rockers, these have a dimple on each side of the valve stem that keeps the rocker aligned with the stem tip. The push rod hole in the head will be round. If it doesn’t have self aligning rockers the push rod hole will be lozenge shaped in the direction across the width of the head. Both rocker aligning systems cannot be used at once so the engine will present one or the other. Self aligning rockers themselves doesn’t mean a roller cam but in a passenger car it moves the probability in that direction. As a note or two the flat tappet cam stock uses a 7.8 inch pushrod the factory (noted as “OEM”) roller uses a 7.2 inch push rod hat is not hardened. The 7.8 inch push rod can be factory hardened or not for those heads with the cast in lozenge shape guide they must be hardened for self guiding rockers they don’t need to be but hardened or nor makes no difference on these.

If the head uses round pushrod holes you might be able to see down the length of the push rod into the bottom of the valley. In the picture that Ericnova72 included you should be able to see the top of the lifter if there is a dog bone linking the lifters in pairs per cylinder and a tip of a spider leg resting on the dog bone this would have a factory or so called OEM* roller cam.

Frankly I don’t see the need to replace rockers, pushrods and especially lifters if there are no indicated problems. Changing these things can invite far more trouble than it solves especially changing flat tappet lifters. There is a modest gain to be had by changing the rockers form the factory 1.5 to 1 ratio to 1.6 ratio rockers, the engine will respond to this as if you put in a cam with about 7% more duration and lift. The factory rocker studs are 3/8ths inch diameter, so you need to order rockers for this diameter stud. Changing stud diameter and going to screw in studs is a bigger technical deal than it looks like which living on a budget in an apartment is a way bigger deal than you want to get into.

Given we’re apparently headed for a recession triggered by tech industry layoffs my fatherly advice based on 8 decades of this political/economic crap is to keep your time and financial exposure low till we see where Putin’s war is going to drag the world economy. I expect this winter is going to be a financial bit*h. With that thought in mind I’d limit my activity to a set of roller 1.6 ratio, 3/8ths stud rockers. This can be done fairly inexpensively and is a day job that presents really good results that you will feel and likely hear for the time and money invested.

* Note that these days the SBC cams are listed as flat tappet or reto-roller or OEM roller. OEM means Original Equipment Manufacturer in this case Chevrolet production line.

- Flat tappet assumed to be self explanatory this pretty much is from from 1955 through 1986 in passenger models and trucks through 1995. There are exceptions.

- Retro-Roller is the current term to define the old blind nose roller cam used to replace flat tappet cams. These can be used in 1955 and up to the crate engine era for Gen I blocks flat tappet or roller. Gen II blocks are different where with simple mods Gen II cams like the LT4HOT can be modded to run in a Gen I block but not so much the other way around.

- OEM roller basically 1987 up except for trucks before 1996 is the step nose cam it uses a unique timing set and a positive bolt on thrust plate. It’s timing gear bolt circle is different from the blunt nose cams so timing sets between these and retro-roller or flat tappet cams do not interchange. Many truck blocks from 1987 up have the provisions for the OEM roller cam. These will exist from raw casting up to finish machined an ready for an OEM roller. These provisions are raised lifter blocks for the taller OEM roller lifter, the valley cast wider to accommodate the space needed for the dog bones, there will be 3 nipple bosses on the main oil galley with each above the 3 middle main cap bulkheads. The front of the timing case will have a football shaped mounting pad sitting at an angle that mounts the cam thrust plate.

There are many excellent books out there on the SBC. I think a good basic to have is this:

It gives a pretty good look at how this engine series has evolved over its long life span and is a great primer on what parts came on which engines and how they interchange where they do. You can for 25-30 bucks gain knowledge that otherwise takes years.


Bogie
 

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Discussion Starter · #5 ·
Putting new flat tappet lifters on a used cam will frequently wipe out cam lobes and force you to rebuild the engine.

Why do you think you need to replace the lifters, pushrods, and rocker arms??
Because I have an engine tick.

First I assumed it was my oil leak, but my oil level is in operating range.

Then I was told to check, tighten, and replace my exhaust manifold gaskets, which were leaking. First I just removed them and drove manifold to head for awhile and just now added gaskets again... ticking never stopped.

So now I'm assuming it's gotta be a lifter tick and if I'm going to replace one, I might as well replace them all.

If I have to replace the cam I will, need one I know of anyways...tired of guessing and not knowing what cam I'm working with.

What lope and duration should I be looking into for my flat tappet l69 motor? If I'm going to change the camshaft, I at least want it to sound somewhat choppy but nothing major...
 

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Discussion Starter · #6 ·
Because I have an engine tick.

First I assumed it was my oil leak, but my oil level is in operating range.

Then I was told to check, tighten, and replace my exhaust manifold gaskets, which were leaking. First I just removed them and drove manifold to head for awhile and just now added gaskets again... ticking never stopped.

So now I'm assuming it's gotta be a lifter tick and if I'm going to replace one, I might as well replace them all.

If I have to replace the cam I will, need one I know of anyways...tired of guessing and not knowing what cam I'm working with.

What lope and duration should I be looking into for my flat tappet l69 motor? If I'm going to change the camshaft, I at least want it to sound somewhat choppy but nothing major...
I'm also raising the motor off of the motor mounts and resting the motor on two short blocks of wood between the motor and motor mounts/frame to replace my oil pan, gasket, and bolts.

Camshaft replacement while I'm at it is perfect timing.
 

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Most often a lifter tick in these engines is also a wiped cam lobe.

But before going off the deep end a mechanics stethoscope from the parts store will help isolate where the tick is coming from. I gather you didn’t replace the exhsust gaskets this needs to be done. Best to use copper or aluminum gaskets or the thick Remflex gaskets. Standard gaskets made of compressed fiber, paper and sometimes with a mesh core are a waste of money, just belly up to the bar and get the good stuff or your going to get to do it again and again and again.

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I'm also raising the motor off of the motor mounts and resting the motor on two short blocks of wood between the motor and motor mounts/frame to replace my oil pan, gasket, and bolts.

Camshaft replacement while I'm at it is perfect timing.
‘You’re getting way ahead of yourself.
‘You need to find the tick first.
if it’s a wiped cam lobe then a cam swap won’t cure it. A complete motor cleaning will be needed. You’ll need to pull the motor to do that.
Use a stethoscope to isolate it then pull the valve cover to check if one or more rockers aren’t moving enough.
If it’s a wiped lobe all those fine metal shavings get dispersed throughout the motor.
 

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Discussion Starter · #9 ·
Most often a lifter tick in these engines is also a wiped cam lobe.

But before going off the deep end a mechanics stethoscope from the parts store will help isolate where the tick is coming from. I gather you didn’t replace the exhsust gaskets this needs to be done. Best to use copper or aluminum gaskets or the thick Remflex gaskets. Standard gaskets made of compressed fiber, paper and sometimes with a mesh core are a waste of money, just belly up to the bar and get the good stuff or your going to get to do it again and again and again.

Bogie
I did use a mechanic stethoscope and the ticking comes from inside the intake manifold on the driver side more towards the front of the engine.. I would assume that is a lifter with the sound coming from inside the intake manifold...

As far as my exhaust manifold gaskets go, I can only use exhaust manifold gaskets that have the seven bolt slots. I bought the Mr gasket copper exhaust manifold gasket set for 60 bucks just to find out that only one side fit and that was on the driver side, when I tried to put it on the passenger side it seemed too short and would not fit correctly because there was only six volt slots on the gasket...

These are what I have in place between the exhaust manifold and heads...
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Discussion Starter · #10 ·
‘You’re getting way ahead of yourself.
‘You need to find the tick first.
if it’s a wiped cam lobe then a cam swap won’t cure it. A complete motor cleaning will be needed. You’ll need to pull the motor to do that.
Use a stethoscope to isolate it then pull the valve cover to check if one or more rockers aren’t moving enough.
If it’s a wiped lobe all those fine metal shavings get dispersed throughout the motor.
I've done numerous of oil changes on this engine, and I haven't found any metal shavings in the oil. I just did a rocker arm adjustment not too long ago and the ticking seems to be coming from the cylinder one valve spring rocker arms, driver's side of course. And the ticking doesn't go away when the engine is warmed up, it actually gets louder at higher RPM with the engine warm.

What kind of drivability issues would I be having if I had a wiped cam lobe ?

Not jumping the gun here, just basing decisions off of what I've already experienced and troubleshooted.
 

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Discussion Starter · #11 ·

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Discussion Starter · #13 ·
Pull the drivers side valve cover and check the rockers movement.
I've done that as well and they all move as they should...

Seems like no matter how much I adjust them it doesn't want to adjust and stop ticking...

With the engine running, I loosen up each one until it starts ticking and then tighten it down and then another quarter inch turn... Only cylinder number one valves start loosening back up and start ticking again...
 

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Can you tell exactly which rocker arm it is that is noisy??
If so, swap it with another 2 cylinders away....see if the tick follows the rocker arm swap, or stays at cylinder #1.
If you swap the rocker and the tick stays home, then you've got a Cam/lifter problem.

Stock rocker arms can wear a ridge in both the rocker sled tip and the rocker pivot ball pocket....a step like that can create a tick that defies adjusting when the rocker is later used with a bigger cam that moves the rocker further in travel, it starts running on the wear ridge at random.
 

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I did use a mechanic stethoscope and the ticking comes from inside the intake manifold on the driver side more towards the front of the engine.. I would assume that is a lifter with the sound coming from inside the intake manifold...

As far as my exhaust manifold gaskets go, I can only use exhaust manifold gaskets that have the seven bolt slots. I bought the Mr gasket copper exhaust manifold gasket set for 60 bucks just to find out that only one side fit and that was on the driver side, when I tried to put it on the passenger side it seemed too short and would not fit correctly because there was only six volt slots on the gasket...

These are what I have in place between the exhaust manifold and heads... View attachment 627584

Only 6 bolts are used the gasket with 3 uses only the inboard 2. The passenger side head is the same as the drivers side just mounts in the reverse direction. You can see this in where the coolant temp sensor of the heads is located relative to the direction the head’s are to the block. The left side the the head temp sensor is toward the front of the engine and is the one used for temp sensing by the factory. The right side head has this feature favoring the firewall direction of the head with the temp sender provision plugged.

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Discussion Starter · #17 ·
Also, keep in mind that a good, low-mileage, used 305 or 350 is likely $300 at the junkyard. I totally get it if you want to do the work, but if it's cost that's important, $300 and about 5 hours gets you a good factory assembly, possibly even an ujpgrade.

As Ericnova said, not ever a good idea to put new flat lifters on an old cam (or vice versa). Very good chance it will wipe a lobe and/or lifter in very short order. You'll need a cam as well if it's flat tappet... which is almost certainly is.

Help us help you out by letting us know why you need pushrods, rockers, and lifters.
Come December 10th, I'll have about $375 to spend on this project. Instead of a junkyard engine, I'd rather spend that money on a new flat tappet camshaft, push rods, and rocker arms. I already ordered the replacement parts for the oil pan and rear main seal replacement, and I've figured out how I'm going to lift the motor without an engine hoist and set it on blocks of wood between the motor mounts and the engine block so that way I have access to remove and replace the oil pan.

While I have the oil pan off, is the perfect time to swap out the camshaft so that way I can perfectly seal the timing cover to the oil pan, eliminating all engine oil leaks from the pan.

At this point now, I need to decide what flat tappet camshaft I'm going to put in it... I'm not going to lie, if I'm going to do all this work and swap the camshaft, I do want it to sound a bit choppy 😉.
 

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Discussion Starter · #18 ·
Seems like no matter what we suggest, you’ve already done it.
why even have a thread if you know it all already.
You are entertaining though!
It's not that I know it all, it's that I realize there is more than one way to skin a cat and I'm more asking questions than making decisions...

There are some decisions that I am stuck with though I'm stuck with replacing the lifters because I strongly assume from troubleshooting that I have a noisy lifter that needs to be replaced.. you guys told me it's a bad idea to just replace the lifters and that I should replace the camshaft as well.. I've accepted that and that's what I have decided that I'm going to do based off of the advice that you guys have given me.

Also I am taking into consideration my budget and lack of tools and what I can do to make this project happen while I have that budget and lack of tools...

There were plenty of times in other forums, where I was told it couldn't be done and I did it... And sometimes it doesn't happen that way, it's all trial and error and a learning experience for me.

But I do appreciate the advice from everyone and I take it all into consideration because I do realize that you guys have much more years of experience than I do but I also know that there are guys who have just as much experience as you do who are telling me that what I'm trying to do can be done.

You can always teach an old dog new tricks... And me, I'm just a young pup in the game and I'm learning more everyday in every way ❤
 

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Discussion Starter · #19 ·
Can you tell exactly which rocker arm it is that is noisy??
If so, swap it with another 2 cylinders away....see if the tick follows the rocker arm swap, or stays at cylinder #1.
If you swap the rocker and the tick stays home, then you've got a Cam/lifter problem.
I know that it's either the exhaust or the intake valve rocker arm on cylinder number one... It's the second one in from the front of the engine on the driver side.

I will swap out both of the cylinder one rocker arms with a set of rocker arms from cylinder number 7 and see if the tick stays home or moves to cylinder number 7.

That's a good troubleshooting trick by the way 😎👍🏾.
 

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At this point now, I need to decide what flat tappet camshaft I'm going to put in it... I'm not going to lie, if I'm going to do all this work and swap the camshaft, I do want it to sound a bit choppy 😉.
If you're going that route, just be aware that the entire TPI setup is perfectly matched to an idle-4500 rpm band. Adding more duration and overlap to get a choppy idle will be a complete mismatch and performance will potentially be awful. You'll lose a ton of torque and likely not make much (if any) more hp. The cam will start to wake up at 3500, and at 4500 the intake and heads will fall flat on its face. If you want to upgrade cams, you need a comprehensive upper-end re-work... different heads, intake, compression, the works. You'll also need to find someone who can burn a custom chip (or several for trial and error) to get it to run right, and even then, your factory ECM won't be expecting the fluctuating/lower vacuum signals and may not ever run right. Above all, the tiny bores of the 305 mean that it will never breathe enough to support the airflow you need for decent power. If you just want a choppy idle and don't mind going slower and getting terrible MPG, you can do it, but I think you'll be remarkably disappointed.

The right way to add more cam on an L69 305 is a multi-thousand dollar proposition with minimal gains because of it's tiny bores. This is why I suggested a junkyard 350. For $300 you can get an instant torque and hp bump over the weekend compared to a tiny-bore 305. The 305 might be 87% the displacement of a 350, but it does not have 87% of the performance capability. You can spend $1000 making a 305 perform as well as a stock 350.... or you could spend $300 on a stock 350.

There is a very good reason why the 305 is not recommended as a performance engine. It's not just "go big or go home," it's, "you're wasting money."

Not trying to be a jerk, just giving you some hard facts. Yes, you can make horsepower with a 305, but you'll spend three times as much and have a less-streetable engine.
 
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