Which 454 to get

[polar]

Well I think my motor upgrade is gonna be under way sooner than later. I am in the market for a Chevy 454 4 bolt . Is there a specific block other than L78 or LS6 that was decent ?

 

[88GMCtruck]

Find a Gen VI 454. They are 96+ vortec motors, and about the best design. Are already setup for roller cam, have nice cast i-piece timing cover, 1-piece rear main, cast valve covers, mech fuel pump boss, and upgraded heads. The Gen V motors (1990-1995) are similar except they don't have the mech fuel pump boss.

 

[BHBurban]

I have a 77k mile '89 454 if you'd like to come get it.

 

[sewlow]

Look at wrecked/retired/dead, class one or class three motorhomes that came with the BBC. A lot of those came with the tall deck block, but I know a couple guys that have found the short deck blocks, which also had steel cranks & 4 bolt mains.
L78 & LS6 blocks are stupid crazy expensive, IF you could find one!
If you're building for power, round port heads can be made to work, but they like lower rpm. Great for towing because they help with low end torque due to the fuel intake velocity at low rpm.
Square port heads are better for BIG power, but aren't really an advantage until the engine gets up into the higher rpm's. You'll need a pretty stout lumpy idle cam or a dual profile to take advantage of the breathing capacity of those heads.
You'll need at least a 780cfm carb on the square ports.
This is just my experience with BBC's. I'm sure that there are other members that have much more knowledge of these engines than I do. Some may even call me out & say I'm way off-base. But like I said, just my experience.
Original square port heads can be found fairly easily, but again, big dinero!
Square port aftermarket heads are more readily found, but as with anything BBC, they ain't cheap.

 

[polar]

Well suprisingly the L78 and LS6 blocks are available in Florida. So a newer block is better than an older block

 

[sewlow]

I like older blocks. Higher nickel content. And they're already 'seasoned'.

 

[88GMCtruck]

I just built a TBI 454 for my truck. Starts on post 17 of my build thread http://www.gmt400.com/forum/showthread.php?9859-88GMCtruck-s-never-ending-88-GMC-build-thread/page2

It's a 96 Gen VI block. I used Vortec 454 Heads (oval port and 100CC chambers for higher compression), dual plane intake, modded TBI, stock vortec roller setup and GM Cruiser cam. It moves out of its own way.

 

[polar]

I will look at your build thread tonight when I have time after studying for class. I plan on going carbureted so it will be real nice.

 

[polar]

For this 454 I plan on building around 500 horsepower and capable of nitrous. Would the 96+ vortec 454 be good for this?