shawnss

iTrader: (8)

Ok here I am stuck on what i want to do. I have really been wanting to build a stout bottom end for the last year or so. heck at one time i even had everything to build a forged 370. i had callies h-beams, wiseco dished pistons with total seal rings and all the bearings and arp studs. then i couldn't make up my mind up and sold it all. Well here I am again not knowing what i want to do. either way the build will have to support boost. it will be turbocharged.

as a goal i'd really like to run low 11s on high boost at the track.. but for the streets a low 12 would do the job. I have ran a 12.5 on a stock 6.0 with 11lbs and a 65 wet shot. but i felt that was about the farthest i'd want to push a stock bottom end.

The turbo i have now will only support up to 750hp at the crank. i think with a 370 or 408 i would have to upgrade the turbo either way to meet my goal.

So do i build a forged 370 or a forged 408 stroker. only thing that has me holding back on a 408 is that some guys have claimed they tend to eat oil because the pistons are being pulled deeper out of the cylinders. Im also just planning on running a set of worked of 317 heads.

the cost difference of the rotating assembly to do a 408 vs a 370 is only about $800.00. so not bad for dang near 40 more cubic inch's.

I am no engine builder by any means and i don't want to be rebuilding a motor 1 year down the road do to poor choices i made during the build.

so let me have it guys. whats the pros and cons of each. Im not going bigger than a 408 either way. thanks for any help guys. As soon as i can make up my mind im ordering everything to complete this build.

Atomic

iTrader: (42)

What turbo do you have now?

My 402 doesnt use any oil and I have been beating on it for about a year, so that statement isnt totally true. As long as the engine is broken in properly (ie, put some load on it soon), the rings should seal fine, and as long as the pcv is vented it shouldnt push oil anywhere.

TurboBerserker

iTrader: (1)

Personally, I very much like the stroked cranks. They do so much for low end torque and really make a turbo come alive. I've read a lot of people saying that 402/8s will eat pistons, drink oil, wreck the block because of problems with the crank, etc., and yet know a ton of people going FAST that have had zero issues.

Basically, I put all that down to a good tune, properly built short block, good maintenance and common sense driving practices.

Spoolin

iTrader: (8)

Either one will get you to where you want to be honestly.

shawnss

iTrader: (8)

My turbo is a Garrett gt4088. according to garrett its only good for 700-750hp. so it wont get me by for long. it worked really well on my stock 6.0 it had quick spool and pulled hard all the way through the rpms. a local guy said its always been way to small of a turbo and has always told me i needed a bigger turob even on a stock engine but it did just fine for me. exhaust side is a bit small but spooled great .81 and the compressor side is a .72 a/r

nonnieselman

iTrader: (10)

what size turbine?

shawnss

iTrader: (8)

according to garrett its a 64.7mm inducer wheel and a 88mm exducer wheels

shawnss

iTrader: (8)

I was thinking of upgrading to a pt88 or pt7675. would a pt88 t4 be to small for a street truck. this truck will only see the track once or twice a year just to see what it run's

Atomic

iTrader: (42)

Too big, actually.

shawnss

iTrader: (8)

So if a pt88 is too big what would be a decent street turbo that could get me into a mid to low 11s. how much hp would it take to get a full sized silverado SS to run 11s... Im pretty high up at 3800ft.