1974-454 What "Mark" do I have?
 

Wikipedia lists BBC stats and GM product designations for passenger cars but I can't find a product code for those used in half ton trucks, specifically the 454 used in the C10 from 1974.

I know it's a low HP engine but what do I look for when researching bolt ons like better heads, cam, intake?

I'm entertaining the idea of a small cam but IIRC any increased lift while running peanut heads may be a problem.

In short: What bolt ons can I add to wake it up?

Re: 1974-454 What "Mark" do I have?
 

The Mark IV is what we think of as the big block after the W-head engines ~65/66 and up to about 90.

Re: 1974-454 What "Mark" do I have?
 

If it's from a 74 good chances it has 049 or 781s, those are best heads you could get for a street motor, AKA junkyard heads. I had each, last one was over 400 horse easy. I wouldn't worry too much bout putting in a bigger cam with whatever head, use matching springs and run it.

Re: 1974-454 What "Mark" do I have?
 

Waking up a 74 big block is easy. Bump the compression to no more than 9-1 and put in a mild cam. stock heads are fine unless you plan on reving it more than 5k. Doing those 2 things will almost double the HP from the factory

Re: 1974-454 What "Mark" do I have?
 

This article says it was used in 74 on commercial trucks - https://itstillruns.com/1974-gm-big-...s-7630732.html
The block should have a stamped number on the front of the passenger side head, might tell you more.
Hagerty shows a 454 in a 2 door stepside longbed for that year though so who knows?
You could go to the GM Heritage Center and download the 1974 Chevrolet Trucks booklet to find out - https://www.gmheritagecenter.com/gm-...tion-kits.html
It shows on page 23 of that PDF document that the C10 had a 454 option code #LF8. With a whopping 230HP advertised.

Re: 1974-454 What "Mark" do I have?
 

Thanks to everyone for the info. It's exactly what I was after.

B454RAT: If I read correctly you were using peanut heads when you got 400HP. What all did you do to get that number?

Re: 1974-454 What "Mark" do I have?
 

10:1, ran 93, 781 heads, comp came extreme energy 268, dual plane intake Holley 3310 750, used manifolds cause trying to fit headers n a G body with 4-speed was tough. Never got the motor 100% dialed in but ran like a mother f’r. Regret selling it.....

Re: 1974-454 What "Mark" do I have?
 

No, he had oval port heads like any 454 from 1974 should have including yours. Peanut ports were 80's.

Re: 1974-454 What "Mark" do I have?
 

Other than tall deck was even any peanut ports used? Most of what Ive seen were 049 n 781s.

Re: 1974-454 What "Mark" do I have?
 

Craaaap! I didn't know that. I was sure I'd read somewhere the low HP 454's had peanut ports. I feel better about it now.

I see some some upgrades in my future.

Re: 1974-454 What "Mark" do I have?
 

Started in 1975
346236.....75-87...oval...OPEN...454, 120cc chamber, 225/116cc ports.

So if that was a late 1974, it could have peanut ports, which IMO isn't a bad thing

Re: 1974-454 What "Mark" do I have?
 

Only reference to peanut ports I’ve found is a 1986 casting.
Post your head casting numbers.
That’ll clear it up.