Ls_Notch

Trying to decide between the two on my turbo build. Going to use a dragon slayer crank, good rods and pistons, stage 3 243s and shoot for 10-1 compression. The turbo is a s480 billet wheel, ultra cover, 1.58 ar. Custom cam, ptc stall, 1.69 glide, holley high ram, 417 motorsports intercooler, holley dominator efi, billet atomizer 225s. Race weight will be right around 3100.
I originally planned on a 370 but I could pretty much do a 408 for the same money, does anyone prefer one over the other and why? Thanks.

allout06

iTrader: (11)

i was shyed away from a 408 to a 390 because of the extra rod journal to crank journal overlap.

IT_SS

iTrader: (5)

I went 370 & saved money by using the stock crank

oscs

iTrader: (19)

First question is what is your HP goal?

I went with a 370 to utilize the stock crank. I also like factory geometry and beefier pistons available with the stock stroke. My goal is 900 so it works for me.

(SS)

iTrader: (1)

370 seems more suitable for boost

soundengineer

iTrader: (16)

408 will always make more power than a 370.....but, you will find that you run out of turbo much sooner on a 408 than a 370...
so if you dont want power to flatline and fall off early, you have to use a bigger turbo to begin with...which means slower spooling...not necessarily a bad thing

and 408's love a twin turbo setup


and remember...
boost just tells you how much restriction you have...
it doesnt dictate how much power you can make

10 psi on a 370 might get you to a good power #
but 10 psi on a 408 will always be more power than the 370
with a 408 you can get to the same power # as a 370 with less boost

Ls_Notch

the setup should be good for over 1000 at the wheels. the turbo is rated to 1400, going to run a aeromotive pro series that's good for 1700 forced air efi. It will be on c or q16. Im wanting to keep a stock deg head and I know there are better ones out there but for the deal I got on these and how well the flow im going to use them for now.