Big Block team AASSSEEEMMMBBLLLEEE! (have a 454 performance question)

[86Peter454]

alright alright i hear you all.

so your all gonna like this then.

had my old man pull a valve cover off (i dont know what heads are currently on the truck) as the tuck is sitting at his shop right now.

it has 781 heads on it lol. possibly some other work too as they have roller rockers too.

so i guess you all win ill just go over these heads and see if previous work has been done to them if not get some mild port work as you all suggested and if bottom end is stock ill do some work there too. id like to run a roller cam (if not already idk what cam is in it) as the other reading ive done says they wake these engines up. not wanting to go too big on the cam though. with mild compression and wanting to keep power band low end small cam would be ideal.

 

[shiftpro]

you can pick up the 96-01 454 vortec iron heads that feature 99cc chambers, bigger ports than the peanut but, smaller than the oval ports for $250 on craigslist. This will up the compression provide better flow and come in under budget. You dont want to pull the engine but you are talking about replacing the pistons? Your goals are possible with these heads, heres just a quick idea of the ballpark you could be in http://www.superchevy.com/how-to/en...power-on-a-junkyard-454-with-simple-cam-swap/

Beware of import Vortec castings... they are kinda like junk. Thin casting, can't really shave them down, valve guides not in line. Other dramas...
My builder says most of the GM BB Vortec heads that came through his shop were cracked.

 

[Honky Kong jr]

Beware of import Vortec castings... they are kinda like junk. Thin casting, can't really shave them down, valve guides not in line. Other dramas...
My builder says most of the GM BB Vortec heads that came through his shop were cracked.

So they are a crap shoot much like small block Vortec heads?

 

[OkieFishMan]

alright alright i hear you all.

so your all gonna like this then.

had my old man pull a valve cover off (i dont know what heads are currently on the truck) as the tuck is sitting at his shop right now.

it has 781 heads on it lol. possibly some other work too as they have roller rockers too.

so i guess you all win ill just go over these heads and see if previous work has been done to them if not get some mild port work as you all suggested and if bottom end is stock ill do some work there too. id like to run a roller cam (if not already idk what cam is in it) as the other reading ive done says they wake these engines up. not wanting to go too big on the cam though. with mild compression and wanting to keep power band low end small cam would be ideal.

That's awesome news on the heads!!

I'd go with something in the 225-235 @.050 duration range. These engines need some cam to wake them up, especially if you stroke it. If my big block ever gets replaced, it will be a 489 with around 225 @ .050 duration and I use it to tow a 10,000 lb fifth wheel around. But right now its runs like a damn champ, so I ain't touching it.

 

[shiftpro]

So they are a crap shoot much like small block Vortec heads?

Just chatting with my builder and he thinks the BB vortec are even worse than sb. He has seen a lot less BB votrec heads than sb
and they were all marginal at best in his opinion.

 

[shiftpro]

That's awesome news on the heads!!

I'd go with something in the 225-235 @.050 duration range. These engines need some cam to wake them up, especially if you stroke it. If my big block ever gets replaced, it will be a 489 with around 225 @ .050 duration and I use it to tow a 10,000 lb fifth wheel around. But right now its runs like a damn champ, so I ain't touching it.

And so what are you running in your 496? What's your head/piston/deck/compression/cam details?
Thanks.

 

[74 Shortbed]

the BB vortec are even worse than sb.

I thought everybody knew that, lol..

 

[OkieFishMan]

And so what are you running in your 496? What's your head/piston/deck/compression/cam details?
Thanks.

Currently mine is just a 454 bored .030 over. Cam is 212/218 duration at .050, peanut port heads, CR around 8.5 to 1. This was done by the previous owner, but he gave me the receipts to back it up. I have since put on a performer intake, msd ignition, msd dizzy, eddy carb, and it runs great. Could use a little more cam in my opinion. I really have to wind it up before I hit the next gear when towing my fiver. If the SM465 ratios weren't so wide it'd do better. Someday I will fix that with a gear vendor overdrive...........

 

[4WDKC]

Just chatting with my builder and he thinks the BB vortec are even worse than sb. He has seen a lot less BB votrec heads than sb
and they were all marginal at best in his opinion.

I havent ran across anyone saying the BB heads crack, just the sbc heads crack