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69Tom 07-31-2020 09:38 PM

1974 454 rebuild questions
 
I've run a bunch of searches on this topic as there's been many a 454 rebuilt, and none seem to give me any specifics on what I'm looking to do. Basically, I'd like to get about 400 HP out of it while keeping it mostly stock, which I've read is pretty easy. Just seems like there's a ton of HP left on the table with these engines. Except I haven't seen how to actually accomplish this.

As far as I can tell, the engine is completely original to my 74 C20, so it's a stock 454. I don't really want to do a stroker and end up buying aftermarket heads, intake, etc.

So what do I need to do for the following:
  1. What style pistons do I want to use?
  2. Where to I want my compression ratio to be at?
  3. How do I want to achieve this compression ratio? Pistons only?
  4. What should I plan on having done to the heads?
  5. What cam is recommended? While upping HP, would still like to keep some good torque as it's a C20 and would like to still tow, haul.
  6. Keep the stock crank and rods, or change?
  7. I'd like to be able to take it on some road trips from time to time, in case this may affect an answer above.

Sadly, as always cost is an issue, so I'd like to keep my costs within reason.

I appreciate the help and sorry for another 454 rebuild post.

Ziegelsteinfaust 07-31-2020 09:52 PM

Re: 1974 454 rebuild questions
 
A comp 268 cam, and full bolt on make a 454 a 400+hp engine.

I would heavily consider a roller cam for use with today's oils, and using the new style blue gaskets. Which helps with oils leaks vs old style gaskets.

You want 8.8-9-1 compression for use with today's gas. Unless your willing to run 92 all the time.

I am not the best with big blocks, but closer to a zero deck you can run the better. It keeps the quench tighter. Unless you have open chamber heads, and then I would consider getting new ones.

Even peanut port heads are capable of laying down serious HP numbers, and a mountain of torque. I mentioned a while ago a friend built a engine with them till he could afford the heads he thought he wanted. He mildly ported the heads himself, and in his 468. It had to be close to 475hp/500tq. It had power from 1000-5000 rpm, and could hit rpm before it really started to roll over hard.

kwmech 08-01-2020 11:37 AM

Re: 1974 454 rebuild questions
 
It doesn't take much to wake up a 74 engine. If I am correct the factory compression was like 7.5 or 7.8 to 1. So bumping it to about 8.5-8.8 will help a lot. Cam as suggested comp 268 with a good valve job and you're done. Unless you are going to race this and spin it up to 5-6 grand all the time, just run the stock heads with a clean valve job. Both of my 454s rarely see over 4000 rpm. All the power is in the bottom end for what I use my trucks for

Ironangel 08-02-2020 10:10 AM

Re: 1974 454 rebuild questions
 
Quote:

Originally Posted by 69Tom (Post 8785111)
I've run a bunch of searches on this topic as there's been many a 454 rebuilt, and none seem to give me any specifics on what I'm looking to do. Basically, I'd like to get about 400 HP out of it while keeping it mostly stock, which I've read is pretty easy. Just seems like there's a ton of HP left on the table with these engines. Except I haven't seen how to actually accomplish this.

As far as I can tell, the engine is completely original to my 74 C20, so it's a stock 454. I don't really want to do a stroker and end up buying aftermarket heads, intake, etc.

So what do I need to do for the following:
  1. What style pistons do I want to use?
  2. Where to I want my compression ratio to be at?
  3. How do I want to achieve this compression ratio? Pistons only?
  4. What should I plan on having done to the heads?
  5. What cam is recommended? While upping HP, would still like to keep some good torque as it's a C20 and would like to still tow, haul.
  6. Keep the stock crank and rods, or change?
  7. I'd like to be able to take it on some road trips from time to time, in case this may affect an answer above.

Sadly, as always cost is an issue, so I'd like to keep my costs within reason.

I appreciate the help and sorry for another 454 rebuild post.

I can attest to the 268H cam. Cant really give any more advice until we know the casting numbers on your heads. Ziegelsteinfaust and kwmech are dead on. The stock rods in the truck 454's are golden! Having hardened exhaust seats installed in the iron heads will insure a long life for both heads and valves. Stock crank is fine as long as your not pounding the motor at the strip and spinning it up past 6K rpm. New springs, Comps steel roller rockers, 7/16" studs w/ARP lock nuts, and 3/8" Comp Magnum push rods and your golden. The 268H cam will work fine with the above. If you can afford forged pistons, use them! Match you pistons to your heads to achieve something in the 8.5 to 9.0 static CR. Oh, stainless valves are a good choice and relatively cheap too. Balancing that rotating assembly to your factory crank is a must and will insure a long life for components as well the motor overall...Find a good machinist!

mattfranklin 08-05-2020 05:20 PM

Re: 1974 454 rebuild questions
 
What these guys said. Also, check out Richard Holdnener's YouTube channel for lots of great dyno tests and discussions.

EDIT:
Here is an example:
https://www.youtube.com/watch?v=h9H6gv2aiVk
I could spend all day on his channel.


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