My 5.3 broke the #7 piston last year and I decided to order myself a 370 from texas speed recently to get it back together. I was gonna be using stock heads for now for budget reasons and wanted to know what would be preferred. I have the 799 heads off the 5.3 and an LQ4 in my shed with the 317 heads that I could use instead. My plans are to keep the engine N/A for a while til I save enough to upgrade the fuel system and possibly transmission, then re-install my D1 Procharger.

Also wanted to check if you guys think LS7 lifters will be fine. I've seen some mixed reviews but Texas Speed suggested them.

And should I upgrade the rockers too? If so any suggestions?

This is what Texas Speed speced out for my engine:

Gen IV Iron Block 6.0 bored to 4.030
-11cc Wiseco Pistons
LS9 Head Gaskets (.051 thick)
227/235 .641/.649 114LSA Cam

Thanks!

 

With that size dish I would definitely run the 799 heads to keep compression decent. LS7 will be OK depending on how high you want to rev it, but those lobes have a lot of lift. Youre getting to roller rocker territory which in turn adds enough weight to warrant heavier springs and probably a better lifter.

Have you already bought the cam?

 

Yea it was shipped today with the engine

these are the springs that were ordered as well
https://www.texas-speed.com/p-5704-t...-seatseal.aspx

Do you know what compression ratio I'd be at with the 799?

 

Depending on your piston deck height around 10:1 even with a 799.

 

I was thinking it would rev to ~6300. Would the ls7s be adequate or should I look into something else? And any suggestion on a particular rocker?

also do you think that compression ratio would be ok for a maxed out d1sc assuming 15-17 psi and running 93 octane?

 

Will be fine. My blow through carb setup on my turbo'd 6 liter Nova is at 15 pounds and about 10.7:1. But for safety I toss some 114 race fuel in there lol. With efi and knock monitoring don't even worry about it.

 

Ok thanks, I was planning on probably adding meth injection as well when I go back to boost so I suppose that will help a lot too.

As for my valvetrain, do you think I should try to return the cam and go for something else? Or would it be worth upgrading lifters and rockers for the higher lift?