454 questions

[Darkrider]

Ok as some of you know...pretty much any of you who have read the build thread for my K3500 aka Project Rehab. Rehab was originally powered by an L19 454 big block V8. At some point along the way it had an L05 350 swapped into it. Now after some thought and comparing prices i have decided to return the truck to being 454 powered. Its DD duties are over with the purchase of the Trailblazer so i can def safely afford the decreased fuel mileage due to the big block engine.
The plan is to buy a direct replacement crate motor or save up a lil more and buy the high performance 454s that the local shop sells.

Now my questions are:

I read that the older TBI 454s used a standard carb intake with an adapter to run the Throttle body on it is this true?

Do the 454s use standard 454 heads on them and not some sort of special head like the TBI 350 that has the TBI specific mounting points for the intake? I would like to be able to just grab some aftermarket 454 squarebore intake and drop a TB adapter onto it to run TBI on it if possible.

Will i be able to transfer all the front accesories from my 350 to the 454? I remember that David needed to locate a 454 specific mounting bracket but i seem to recall that was for A/C.

 

[Darkrider]

One more question....I know the 6.2 diesels required a special oil pan to clear the IFS front differential. Now does the 454 require one as well or can i use a standard 454 oil pan under there and still clear the front diff?

 

[sewlow]

For a 4X4 BBC, I don't know if you really need the square port heads. The smaller round ports would help to make better low end torque. The higher velocity of the air/fuel mixture, at a lower RPM, with the round ports, does that. A good 3 or 5 angle valve grind would help. Matching the heads to the intake would probably be all that I would do, in addition to the valve grind. Don't think that I'd even do any smoothing out of the intake runners on the intake or the heads. That pebbly roughness inside those will help to atomize the fuel better in the lower RPM's (1500-4500) that a 4X4 usually works in. The square ports are an advantage more in the upper RPM range. (3000-6500)
Just my opinion, though. Let the bashing begin! Lol!

 

[supertrucker1978]

My 89 has a 454, although I haven't had the heads off I do know I have an adapter plate. I had to replace both the gaskets for it. My 454 has alot more idler pulleys compared to my small block so I'd have to guess the brackets are different.

 

[Darkrider]

Hmmm ok...well that answers the adapter question. There is a reason i asked about the oil pan especially....See a friend of the roommates has a former drag racing 454 sitting in their garage i could grab for around 1k. I figure if i can get it into the truck without a ton of changes i could use the money saved vs buying an OE replacement motor to get this motor freshened up with new gaskets and other parts to make it work in my truck.

 

[supertrucker1978]

Well, if it has a drag pan on it it wont do you any good in the truck. They have baffles and trap doors so the oil pickup always stays in the oil during a hard launch.

 

[Darkrider]

Well, if it has a drag pan on it it wont do you any good in the truck. They have baffles and trap doors so the oil pickup always stays in the oil during a hard launch.

Fair enough...just wondering if a standard oil pan will work...

 

[supertrucker1978]

Once my truck stops dripping I can go check out what oil pan I have.

 

[454ss]

I have never had any oil pan issues when swapping in a 71 402, 78 454, or a new 502 crate, I always used whatever pan was on them when I got them. these were installed in a 90 k2500hd. brackets are all specific to the big block just like they have always been and I got them from the dealer but they seem to pop up on ebay a lot.