If I could loose 1500# that would be awesome!

 

347 @ 11 psi went 10.93@124. I weigh in at 4500 race weight.

 

I have been happy with my 370 thus far. If you turbo is currently sized for your 6.0L then I would not change the displacement unless you are looking upgrade the turbo as well. Like mentioned in an earlier post, the 370 will be nicer on your budget and will be able to hold plenty of power. That is one of the main reasons I chose a 370 myself.

 

if you can swing it 408. other wise the 370 will be good.

 

or turn it up to 15-16psi

 

408 = more torque, ridiculously "quick" spooling, more backpressure worries, more expense, more power with less boost (e.g. either more total power or easier tuning or more compression)
370 = cheaper in the short run, better mpg, lower torque and exhaust pulse (so "slower" spooling), need more boost to make the same power, so more tune, lower compression, better gas, etc.



**quick / slow are relative


Personally, everything you've said = 408 to me. However, 600-700 hp will be easily attainable on the 370 as well, just slightly different configuration.

 

With having to pull it out and have the motor rebuilt in the first place I think it would be worth the extra $1300 or so to go out to the 408. I know I will deffinetly have to get a bigger turbo.

I just wonder how the log style setup will hold up to that much motor and back pressure. Either way im thinking about keeping the compression close to 10:1 for low end driveability and run it between 12 - 14# of boost.

 

As long as you don't mind running alcohol injection, or race gas.

 

I have an alkycontrol kit sitting in the spare bedroom right now. I have been runing 11# on my stock LQ9 for over a year without it so I don't see why a forged motor wouldnt handle that much.

 

I LOVE my 10:1 370 with 165 kpa of boost.