Hey guys, Please correct me if I am wrong, both of this setups are made from a 6.0L block right? 370 you replace pistons with a bigger size and 408 are pistons + stroke lenght right?
I have been reading much about how to get to 400rwhp in a 5.3 and it seems kind of hard cause I have done pretty much I can do for mine and I still am far from 400rwhp.. The point is, I think its time to improve to a either 370 or 408 setup, I want to stay N/A for now.. I would love to get a turbo in my setup BUT I do a lot of sand drags (100 yards) and I am affraid "Turbo lag" would be an issue here..
So long story short, I need a fast revving-high torque engine.. Should I go with a bullet proof 370 or 408???
Please guys any advice would be greatly appreciated!

 

There is no turbo lag on a proper staged start. Just saying.

I have a 370 only because I didn't know about the 408 crank when I bought my rotating assembly and that crank had just come out. If I could do it again I would have gone 408.

 

Yep, i would do 408 also, could split the difference and do a 383 with your 5.3 if you dont already have a 6.0

 

Yes, both the 370 and 408 use the 6.0 truck iron block and both are bored out to 4.030". The 370 uses the stock stroke of 3.62 where as the 408 uses a 4" stroke rotating assembly.

 

Agreed, 0 turbo lag when staged properly. Boosted the 370, NA I would do the 408.

 

Do you people that claim zero turbo lag actually have a turbo? I have a turbo in my Cobalt SS and it's a small twin scroll unit that has minimal lag, but it still has lag down in the low rpm until boost build up. That's the nature of a turbo. Sure, there are ways to minimize it, but I would never say "zero" lag.

 

I think that running in 4LO(like we always do) will help a lot with turbo lag cause the engine is reving REALLY FAST in each gear, but wouldnt that mess up with the blow off valve and stuff like that? I dont know much about turbo other than I would LOVE to have one, I was just trying to stay away from that "lag" cause such a short race.. (5.60 sec in 1/16th of a mile [sand] is my current time)
So what should I be looking fw to? 408 or 383 low compression with a quick turbo? Any ideas or numbers on turbo size I should use, a/r, etc etc??
Thanks again!

 

Just depends what your goals are. You can turbo that 5.3 of yours and make just as much and more power than a n/a 408. My stock 5.3 with a comp 212/218 low lift cam and a trick turbo kit on 9lbs boost made 460/480 through heavy 20" wheels.

 

Keep in mind that turbo lag is an issue when trying to punch it from a roll or when not stalling up the motor. I doubt that people stalling to 3k at the line are noticing any turbo lag when speced out correctly.

 

This^