the ls3's wont really lower the compression it will raise it .3 from stock. the 5.3 had low 8.8:1 compression, i didn't like it near as much as the 6.0. it didn't have any bottom end compared to this motor stock. my cam is stock right now because the comp cam i had was shot. (wont buy from them again) i want to keep some good bottom end this time around, at 6020lbs i need it. makes the truck way more fun to drive around town. i figure if i did get the ls3 heads i would port and polish them. i heard tea had a good cnc for them but their site wont load so i don't know the cost on it.

 

Ok I understand now. I'll be putting my Patriot Stg 2's and a cam on this winter since I've already got them. BTW I've had 3 comp cams go flat over the years however, they were solid flat tappet lifters not roller. Your truck sure as hell runs good at that weight! It gives me hope on my HD. I weighed it at 5050 unloaded but 6020 like I drive it loaded.

 

TURBHOE what psi were you running for the 5.3L time, that's impressive!

I had a buddy with an lq9 that put ls3 stock heads and intake from his camaro on it. It made a huge difference up top compared to the 243's but the 243's were a lot stronger every where except WOT

 

the 12.33 run was just over 12 psi.

thats what i'm afraid of, at this weight i need more than just top end power.

 

I know compression helps lowend and over all power, but how does one balance that CR# with boost# for best of both worlds. General answer please....I know this has many aspects depending on the application.

 

depends on the fuel you are running and cylinder pressures. The higher the psi, the lower the cr you want. if you run a lower psi, the higher cr you can have.

 

I know a few yrs ago (2008) when I bought a built short block 9.5 was the accepted best compromise of cr with street boost on 93 and meth. That's what makes these stock ls motors so responsive to boost. I'm sure things have changed since then as technology keeps moving on. Still not a bad place to be.