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1995 454 converstion to Vortec heads questions

Posted: Sat Jul 31, 2010 1:50 pm
by racerx1622
Hi,
I've already searched through the posts, but still have some basic questions.

I have a 1995 K2500 truck with a TBI 454. (256k miles)
As you know, it has the "peanut" heads. I have a burned valve, and a couple broken exhaust studs from trying to replace the exhaust manifold gasket.
(which didn't happen)
Since I have to pull the heads, I'm putting a set from a 1998 truck (Vortec) heads on.
I want to get all the parts I need before I do this, as I need this truck.

I know I need a Vortec intake manifold, but the '96 and newer went multiport, so I guess if I want to use my TBI I have to buy a new Edelbrock.
>>Should I use the pushrods from the Vortec head motor or my original?
>>The exhaust manifolds look like the same bolt pattern, will they work?
Since i'm tearing it down, I'm going to replace the timing chain, and put in a new camshaft.
I use this truck for hauling a car, any recomendations (with the Vortec heads)....

Basically anyone who has done this or know of any issues, I sure do appreciate your time to reply.
Barry

Re: 1995 454 converstion to Vortec heads questions

Posted: Sat Jul 31, 2010 2:25 pm
by Alan Roehrich
If those Vortec heads have non adjustable valvetrain, you'll want to convert them to adjustable before you ever put them on. You can get a special stud that is 3/18"-16 on the bottom and 7/16"-20 on top, but I prefer to do a proper conversion with a standard stud that is 7/16"-14 on the bottom and 7/16"-20 on the top.

I'm not sure which intake will line up best with the intake ports on the Vortec heads, but I would not buy a dedicated TBI intake unless I had to. A good true high rise oval port intake for a 4 barrel combined with a Trans Dapt TBI adapter has worked better in the past for me.

You'll do better with 3/8" pushrods and guide plates, especially if you're going to run a decent aftermarket camshaft. Since you will likely convert to adjustable valvetrain, you may need to get a set of pushrods that are not stock length. Get the geometry wrong on a big block Chevy and you'll be replacing pushrods, rockers, valves, and valve guides regularly, not what you want to do if you need that truck.

I've successfully used a Comp X4 262H in a heavy work truck with a 454 TBI, and an automatic transmission with a stock converter. However, it had a 3.73 gear, headers, and dual exhaust. It had early model closed chamber oval port heads, not Vortec heads. It ran well, puled even better, and got decent fuel mileage as well. If memory serves correct, it was degreed in at 107 or 108, and the truck liked about 10-12 degrees of base timing.

Re: 1995 454 converstion to Vortec heads questions

Posted: Sat Jul 31, 2010 4:47 pm
by In-Tech
I'm pretty sure 1990 was when the genV block/heads came out, so you shouldn't have any gasket issues but you'll want to verify. You can use the L29 vortech MPI intake with your 95 computer but it will require a custom "chip" to change it from TBI to MPI. I can help with that and will send you a pm. As another mentioned, converting to adjustable valvetrain is recommended.

Re: 1995 454 converstion to Vortec heads questions

Posted: Sat Jul 31, 2010 11:33 pm
by racerx1622
Thanks for the info Alan.

At this point, I was looking to purchase the Edelbrock 3764 intake.
But, I looked up your comment on the adapter, and find the Summit SUM-226022 intake, and an adapter would save me $80.

Pro's and Cons to using the TBI ready intake or the Performer with an adapter anyone?

Re: 1995 454 converstion to Vortec heads questions

Posted: Sat Jul 31, 2010 11:50 pm
by Alan Roehrich
The 3764 has smaller ports than your Vortec heads, 1.4"x1.6" vs. 1.6"x1.9" for a 7161 that will more closely match your heads. That intake will choke off your new heads. I'd use a 7161 or a 7561 and an adapter. I never liked the plain Performer either, it isn't enough better than a stock intake for my money, it's not even as good as a 396-350 intake. Others may feel different.

Re: 1995 454 converstion to Vortec heads questions

Posted: Sun Aug 01, 2010 2:37 am
by racerx1622
Ok, I've been searching for two hours.

does anybody know of a website that provides the engine specifications for the 1995 Chevy (GM) 454?
Specifically, Cam specifications.

Thanks,