Debating on stroking out a tired 4.8L (383)for a single turbo build.
After reading some articles about the piston coming out of the bore at the end of the stroke, I decided I would like to run a crank with a 3.9 stroke. I need to know how to figure out what size piston I am going to need with this build. Obviously don't want to raise compression if I can help it. I've noticed K1 sells a 3.9 kit but the compression it to high for my liking. How do I determine what piston I will need? Any suggestions on who I can get to make them (assuming no off the shelf ones are available)?

862 heads (not milled)
Ls9 Head gasket

I would appreciate any help or advise. Or should I just go with a 5.3/5.7forged rotating assembly?

 

Definitely go with anything other than a 4.8 rotating assembly.

 

What size connecting rods with this 3.90 stroke crank?

A 6.098 connecting rod would needs a piston with a compression height of 1.192 to reach zero deck and a 6.125 rod will need a CH of 1.165. Look for dished pistons to keep the compression down.

 

What compression are you targeting with this turbo build?

 

Awesome. Thanks. Would probably be 6.125 . I know that makes for a small piston.

 

No specific ratio. Just want to keep it low for boost.