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Discussion Starter · #1 ·
Hey All,
New to the forum and to hot rodding in general. I recently bought a 1970 C-10 with a 69-70 454 BBC in it. I did not get a lot of information from the former owner as I do not think he built the motor. So here is the information that I have checked on myself to the best of my ability. The block was built between 69 and 70. The numbers on the heads were originally on a 427. There is a performance cam in it but I do not know the particulars of it. It has a 600 CFM Holley on it from what I can get from the numbers. Turbo400 transmission and a 3.55 rear end.
What I am looking for is what would be my next step to help boost the Horsepower? I am not looking to make this thing crzy fast. Just a nice crusier with the ability to turn the tires and have some fun.
I have been told if I were to add a 750 cfm carb that I may get up to another 20-25 hp. Is this true? Is this reasonable?
I look forward to your comments and advice. Thanks in advance.
 

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a major question i would ask is what 427 heads. the majority of the 427 heads that where produced from 66-71 would be decent performers to use, but then you have 72-95' 427 truck heads that where junk smog heads made to produce less than 250hp. if you have one of the older heads then i would say you need to invest in a set of heads like these:
Summit Racing SUM-152125 - Summit Racing® Cast Iron Cylinder Heads for Big Chevy - Overview - SummitRacing.com

they aren't the greatest but like you said you dont want crazy power, just enough to have some serious fun (i assume)

the 600 is too small for that 454 so that absolutley needs to be the first thing to go. a 750 vac sec carb like this one would be great:
Holley 0-3310S - Holley Model 4160 Adjustable Float Carburetors - Overview - SummitRacing.com

then, i would ask, what exhuast does the car have on it. it needs headers, and 2.5" pipe with decent mufflers (i recomend dynomax products)

next, what type of distributor does it have, please tell me it isn't an old points one

either look up or post the numbers off the heads to give us a better idea of what they are.

So first i would change the carb, next make sure the ignition and timming are what and where they need to be, then look into the exhuast, next before i changed heads i would look into changing out the 3.55 gears to a shorter gear like 3.90-4.10 since the truck is upwards of 4500+lbs, then after that if you still want more i would look into changing the cam and heads.
 

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Discussion Starter · #5 ·
I'll look into the heads to get a solid answer on what year they were made. Regarding the carb. The current carb has an electric choke so would this carb be a better choice?
Holley 0-80770 - Holley Street Avenger Carburetors - Overview - SummitRacing.com
The truck does have headers thet go to 3" stainless exhaust. I think there are flow masters on it. I will have to double check that too.

I beleive the distributor is an MSD with HEI.

Now for the rear end. It has a 12 bolt chevy in it now. Would I have to change the carrier also in order to change the gearing?

The more I look into it. I am finding that who ever did build this vehicle originally, tried to use pretty good quality components.

Thanks. This certainly helps point me in the right direction.
 

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I'll look into the heads to get a solid answer on what year they were made. Regarding the carb. The current carb has an electric choke so would this carb be a better choice?
Holley 0-80770 - Holley Street Avenger Carburetors - Overview - SummitRacing.com
The truck does have headers thet go to 3" stainless exhaust. I think there are flow masters on it. I will have to double check that too.

I beleive the distributor is an MSD with HEI.

Now for the rear end. It has a 12 bolt chevy in it now. Would I have to change the carrier also in order to change the gearing?

The more I look into it. I am finding that who ever did build this vehicle originally, tried to use pretty good quality components.

Thanks. This certainly helps point me in the right direction.



yup that carb would work just fine. sounds like the exhust is fine, and it's good that you have an HEI distributor. the next thing i would do would be to buy a cheap timming light (normally around $20 at a parts store) a new set of plugs and wires, unless you can tell that the ones on there are realitively new, then check your timming. here is a video what will help with that.


as far as changing gears in the rear, no you should not have to change out the carrier in order to change out the gears since the gears that are already in there are 3.55
 

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Carb for 454 chevy

I looked on Holley's Interactive Carburetor Selector and they recommend these two carburetors for a mildly modified 454 motor.
0-80531
850 CFM Four Barrel Street Carburetor
Electric Choke; Vacuum Secondary; Model 4150™; Calibrated for 502 Crate Motors or other High Performance Big Block Engines
0-80870
870 CFM Four Barrel Carburetor
Electric Choke; Vacuum Secondary Street Ready out of the box; Two adjustments and go. If it were mine I would get the 4150 model, easy to tune. They have been around longer than the Street Avenger.
 

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it all depends on what rpm you plan on turning the engine to. I just use the same calculator and it came up with 750-870cfm carbs

but i pluged in that you wouldn't be turning it over 5500rpm (which from your discription, I assume the motor wasn't built to go over). any carb in this range should do just fine. ive never used one of the street avenger carbs but i have heard they are very tune friendly, but i have used the 4160 and 4150 models and i have found them to be tune friendly as well.

like i mentioned, any of these carbs in this range would do just fine, i know that you want the elc choke and you can get the 4160 and 4150 models with elc chokes as well.

go to Holley.com and use their carb selector, put your estimated information in and it will give you all the carb pn #'s for you to look into.
 

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Hey All,
New to the forum and to hot rodding in general. I recently bought a 1970 C-10 with a 69-70 454 BBC in it. I did not get a lot of information from the former owner as I do not think he built the motor. So here is the information that I have checked on myself to the best of my ability. The block was built between 69 and 70. The numbers on the heads were originally on a 427. There is a performance cam in it but I do not know the particulars of it. It has a 600 CFM Holley on it from what I can get from the numbers. Turbo400 transmission and a 3.55 rear end.
What I am looking for is what would be my next step to help boost the Horsepower? I am not looking to make this thing crzy fast. Just a nice crusier with the ability to turn the tires and have some fun.
I have been told if I were to add a 750 cfm carb that I may get up to another 20-25 hp. Is this true? Is this reasonable?
I look forward to your comments and advice. Thanks in advance.
Have you driven it? If so, do you think it is slow the way it is? The reason I ask, is because w/the parts you have on it now- unless something is radically wrong- it should annihilate the tires and run strong up to at least 5500-6000 rpm.

Has the timing curve been sorted out yet? If not, you need to see what the initial and total timing is, etc. Help w/the HEI distributor including timing is here.

I'd be interested in knowing the casting numbers of the block (and the suffix if it is still there) and especially heads, if possible. The heads have the casting numbers under the valve covers. Info to help ID the heads and block is here, should you want to double check.

Good luck.
 

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^^^^ that is kinda my thoughts as well, it could be that the 600cfm carb he had on there was choking the motor some but it still should have felt like it pretty good power until around 4000 rpm.

if he goes through everything, carb, ignition + timming, and it still doesn't have much power/tq then i would have to think that it's got a pair of the later truck 427 heads on it. but honestly still even with those it should still be making atleast hi 200's hp and high 300's tq if tuned right
 

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WFO
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6000 rpm might be pushing it, I agree. But 5000-5500 at least- I ran a 600 cfm Holley 4010 on a Pontiac 455 and it went 12's in an all steel Camaro, so I know for an engine of that displacement it's enough to do at least that. Not saying a Pontiyak engine is like a BBC, just comparing the displacement/rpm.
 

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Discussion Starter · #13 ·
Ok. Sorry for the delay in response. Life sometimes gets in the way.

Anyway. I did some more digging. The list number on the carb is 50418. From what I can gather searching the internet is thatthis is actually a marine carb. Also the more scary part is that this may be as small as 450cfm. But I couldn't find anything conclusive. But the largest CFM number I came across with this particular list number was 600. From what I could see the carb was inteneded for a 302. Also there is a small metal tag on the carb with Motorcraft stamped in it. Regardless this thing is outta here.
Regarding the heads. The 2 number series stamped in the front flange of the RH head were TO114OLB and 11K114538.
So as of now the main hold back seems to be the carb for sure. To answer cobalt327's question. Yep. I have driven it. It has enough power to bounce the front end up and down when you goose it and if you use the slap shifter you can squak the tires when shifting from 1st to second but nothing that I think I would expect from this size motor. Maybe it is just me and I am not use to this heavy of a vehicle.
Another question regarding the new carb I am planning to install. Do I need to do anything with the fuel pump? Is the pump I currently have sufficient to keep up with the larger carb? Also do I have to worry about running this engine too lean?
As far as the carb is concerned I am leaning toward the street avenger style.
Thanks to everyone for all of your help so far.
 

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WFO
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Ok. Sorry for the delay in response. Life sometimes gets in the way.

Anyway. I did some more digging. The list number on the carb is 50418. From what I can gather searching the internet is thatthis is actually a marine carb. Also the more scary part is that this may be as small as 450cfm. But I couldn't find anything conclusive. But the largest CFM number I came across with this particular list number was 600. From what I could see the carb was inteneded for a 302. Also there is a small metal tag on the carb with Motorcraft stamped in it. Regardless this thing is outta here.
Regarding the heads. The 2 number series stamped in the front flange of the RH head were TO114OLB and 11K114538.
So as of now the main hold back seems to be the carb for sure. To answer cobalt327's question. Yep. I have driven it. It has enough power to bounce the front end up and down when you goose it and if you use the slap shifter you can squak the tires when shifting from 1st to second but nothing that I think I would expect from this size motor. Maybe it is just me and I am not use to this heavy of a vehicle.
Another question regarding the new carb I am planning to install. Do I need to do anything with the fuel pump? Is the pump I currently have sufficient to keep up with the larger carb? Also do I have to worry about running this engine too lean?
As far as the carb is concerned I am leaning toward the street avenger style.
Thanks to everyone for all of your help so far.
The code TO114OLB contains the suffix (LB). It shows up as either a '65 325 hp 396 or a '69 335 hp 427. Thing is the partial VIN (11K114538) would seem to indicate the engine was from a year ending in 1.

The casting number back by the tranny on top of the block would help narrow it down along w/the date code from the same area, opposite side usually.

The casting number and date from the heads will also help.
 

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Block casting number 3969854.
That is one of those numbers.:smash: It shows up variously as a 396, a 402, and a 454.

There's no consensus, but I would lean towards it being a 402- going by the performance you described (although a 402 can run strong) and by the partial VIN that indicates a date of '71 (there were no 427 BBC in '71, except tall deck truck- it's not one of those, is it?). If you can find the date code back by where you found the c/n that may help. It's a code like "D 12 1", or something like that.
 

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Discussion Starter · #19 ·
Ithink what I called the suffix OLB is really CLB. With more research and the rest of the codes I think the motor is (or at least was) a 402 out of a impala or chevelle. I am ruling out the camaro for now since that shows that model as a manual. The heads are coming up as a 73-85 454. Do you agree? So the motor was originally up to 300 hp stock before the lrger heads were added along with the cam,headers, exhaust, updated ignition.

Is there anyway to determine CID without pulling the heads?
 
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