My younger son will soon be replacing a tired LS motor with a new rebuilt
LS motor and I'm considering letting them rebuild the old motor as a project.
Do any of you have suggestions concerning how much to build and can
we get a big HP increase without going Forced induction?

Thanks,

 

I'd just buy a GSR motor and work with that. You will see a much better gain for the price

 

Build it up for an lsvtec turbo project if you are that serious about it. With some strengthening to the bottom end, I don't see why you couldn't get 300+ whp out of it.

 

bolt-ons, crower 404's with b16 pistons will net about 170-180 whp if tuned correctly. pretty simple streetable set-up with an awesome powerband/torque curve