[ceruddick]

Hey all,

I just joined the site after visiting several times for ideas and tips. I am contemplating my first engine build. I know absolutely nothing about tearing a motor down and rebuilding it from the ground up. I'm a shade tree mechanic that can keep the cars going, but have generally outsourced big jobs. With that said, I need a site where I can openly ask questions and learn without judgement or fear to ask.

I have a 68 C10 pickup with 350 sbc (3970010) from a 69 Impala. I want something that will run on pump gas and can be driven frequently. I'm simply looking to get 325 to 350 HP from my motor.

The build will include stock 76 cc heads, 2 barrel Rochester carb, plain headers.

In this build, I will replace the 2 barrel for a 600 Holley/ Edelbrock Performer intake. Update to the HEI distributor and hotter coil, new cam, master rebuild kit with pistons from Summit Racing, Eagle 5.7 I-beam rods with floating pins, reusing the stock crank.

Lets start here,
1. How much horsepower should I expect to produce by making the above changes?
2. Can I reach the 350 HP mark with this equation or do I need to buy new heads (say Vortec heads)?

[Hotrod 80]

[QUOTE=ceruddick

I have a 68 C10 pickup with 350 sbc (3970010) from a 69 Impala. I want something that will run on pump gas and can be driven frequently. I'm simply looking to get 325 to 350 HP from my motor.

The build will include stock 76 cc heads, 2 barrel Rochester carb, plain headers.

In this build, I will replace the 2 barrel for a 600 Holley/ Edelbrock Performer intake. Update to the HEI distributor and hotter coil, new cam, master rebuild kit with pistons from Summit Racing, Eagle 5.7 I-beam rods with floating pins, reusing the stock crank.

Lets start here,
1. How much horsepower should I expect to produce by making the above changes?
2. Can I reach the 350 HP mark with this equation or do I need to buy new heads (say Vortec heads)?[/QUOTE]

1hp per inch is doable . I would opt for a flattop to raise compression. and cam choice will be important . If you have to buy the intake anyway i would go Vortec on the heads . David Vizzard has a few good books about making SBC HP . the 4160 Holley is proven , unless you need a double pump then i would move to a 650 cfm . You should be able to make 290-300 to the ground fairly easily with good drivability.

[ap72]

a 325hp 350 is REALLY easy to make. Since this is a truck that will be driven often I would keep it simple. You heads will dictate a large part of your build, so what casting number is on your heads? Also, at this power level low lift flow is EVERYTHING so I would get a good 30º valve job. If your guides are trash (which they probably are) then you may want to look at a set of aftermarket heads before you rebuild yours- its usually about the same price and you gain a LOT of performance.

Also, I assume you want to run 87 octane?

Manual or Auto transmission?

Why do you want to use Eagle rods? What is wrong with the ones you have?

Flat top Pistons would be a good choice, BUT make sure the have the right compression height, 1.560-1.565". most rebuilder pistons do NOT have the right compression height.

Keep your cam small and a moderate LSA, something in the 215 range for duration and 108-110 for LSA, single pattern.

You didn't list them but long tube headers are a MUST, they will make a world of difference, 1 5/8 primaries are fairly common and relatively cheap. Dual exhaust really isn't needed at this power level, but a GOOD exhaust is, get 2.5" collectors, and using a good Y connection bring it to 3" and then dump it before the rear tire, its cheap and adequate for your power level.

Edelbrocks tend to have better mileage than a holley but I would use whatever carb you are most comfortable with, if you never worked on either an Edelbrock is the easiest to tune IMO and the secondary system is much better for a street driven car.

[ceruddick]

I was planning to buy new rods simply to have brand new equipment in the motor. However, after I read the replies here, I think I will skip the rods/ reuse the ones I have. Then, use that money for a new set of Vortec heads. Or I have the option to buy a newly rebuilt set of double hump heads with 2.02/1.60 valves, new springs, guides, etc. Believe they are 186 cast number. The guy wants like $400 for the set.

Which is the better option for power? I want to create as much horsepower as I can with minimum $$$

Sorry, I do have the long tube headers on it right now. They aren't the fanciest things, but they get the job accomplished. It runs to dual exhaust pipes dropped off after the cats.

[ap72]

Originally Posted by ceruddick

I was planning to buy new rods simply to have brand new equipment in the motor. However, after I read the replies here, I think I will skip the rods/ reuse the ones I have. Then, use that money for a new set of Vortec heads. Or I have the option to buy a newly rebuilt set of double hump heads with 2.02/1.60 valves, new springs, guides, etc. Believe they are 186 cast number. The guy wants like $400 for the set.

Which is the better option for power? I want to create as much horsepower as I can with minimum $$$

Sorry, I do have the long tube headers on it right now. They aren't the fanciest things, but they get the job accomplished. It runs to dual exhaust pipes dropped off after the cats.

The Vortec heads are better BUT a lot more costly. Since you're looking at the 300-350hp range I would go with the 186's. With the added compression you can move your cam up to about 220 degrees, with a hair more exhaust duration but DON'T over cam it.

If you can get a deal on a good set of rebuilt Vortecs then go that route, but don't buy them new, if you're looking to spend that money I'd go with a 200cc chinese head. Also, with any factory stock head stick with the 1.94/1.5 valves if you can- it takes a LOT more work than most people do to get the 2.02/1.6 valves to work as well.

[ceruddick]

First, thanks for all the info. You guys are great, so helpful. I have a local guy that has a set of used Vortec heads he wants to sell. They are 67 cc chamber, 175 intake runner. He bought them new from Summit Racing about 3 months ago. He switched from a sbc to a bbc and sold his long block. Local machine shop I chose said they checked out good. I think I will get these heads and leave the 186 alone.

If I have these heads on the motor with a flat top piston, what is my best option for a cam? I don't drive the truck everyday, so I am more than willing to trade some mileage for a little bit of power. I want the truck to sound as good as it runs but keep it balanced.

[ap72]

Originally Posted by ceruddick

First, thanks for all the info. You guys are great, so helpful. I have a local guy that has a set of used Vortec heads he wants to sell. They are 67 cc chamber, 175 intake runner. He bought them new from Summit Racing about 3 months ago. He switched from a sbc to a bbc and sold his long block. Local machine shop I chose said they checked out good. I think I will get these heads and leave the 186 alone.

If I have these heads on the motor with a flat top piston, what is my best option for a cam? I don't drive the truck everyday, so I am more than willing to trade some mileage for a little bit of power. I want the truck to sound as good as it runs but keep it balanced.

For an off the shelf cam a VooDoo 268 is a popular cam with that combo. I would not go any bigger! A VooDoo 262 on a 106-108 LSA would also be a nice cam with a little more midrange punch than the 268.

The 268 is a hair too big for stock Vortecs IMO, but a lot of people use it. The 262 on a narrower LSA would be better suited to stock heads, BUT If you have a good valve job and some bowl work done the 268 works great.

[my87Z]

i would go with the vortecs, just a much better performing head. and as AP mentioned you really need to look into whether the pistons you are buying are 1.560" as most cheap rebuilder pistons are sold at 1.540" because they take into account that you may have plained the deck of the block .020". I agree that the stock rods are likely just fine, i would just have everything inspected by a decent machine shop first, they may need to turn the journals a bit for a clean surface.

a 600-650cfm vac secondary carb would work just fine. the full lenght headers are a must like mentioned earlier.

for a cam this would make for a nice mild motor:
http://www.summitracing.com/parts/HRS-112571-12/

i'm a little patial to Howards, i'm not much for the 112LSA, but something in this range would do fine, it could be used with the stock stall and pretty much what ever gears are in the truck.

one thing i would pay attention to your quench area dont do like the average "jo-sho" and just but .040" head gaskets, acutally measure the distance from the piston head at TDC to the top of the block, this measurement + your head gasket thickness should be about .040-.046". so if you end up with .015" measurement here then you should be looking for a head gasket with a thickness of about .025" to give you the propper quench area.

[techinspector1]

Originally Posted by ceruddick

They are 67 cc chamber, 175 intake runner.

If I have these heads on the motor with a flat top piston, what is my best option for a cam?

I might lean more toward a 12cc piston such as this one...
http://kb-silvolite.com/kb_car/perfo...hp?action=comp
I would want to keep the static compression ratio fairly low, so that I could run a modest cam. With your 67cc chambers and 12cc pistons, you would be at 9.33:1 and might use a cam such as this....
http://www.cranecams.com/product/car...detail&p=23759
This cam, when matched up with the 9.33:1 static compression ratio, will yield an 8.43:1 dynamic compression ratio. That'll work well with pump gas if you build the motor with a tight squish (0.035" to 0.045"). I like to err on the side of caution, particularly with a heavy vehicle like your truck.

Get this book and read it through several times. You'll begin to get a feel for what works and what doesn't....
http://www.amazon.com/How-Rebuild-Yo...9411225&sr=8-9

As far as rods, check with your shop and find out what they want to magnaflux, shot peen, side clearance, re-size and replace the bolts with ARP bolts and weight-match. You may be better off buying a set of 8 from CP for 130 bucks....
http://www.competitionproducts.com/C...ctinfo/804335/