so take the stock lq4 bottom end, add stock 4.8 heads and 93 octane gas and what kind of STOCK hp do you end up with at crank?

 

if the only difference between the LQ4 and LQ9 is compression and tuning-
with a stock level tune- id expect another 30hp (1 point being about 4%, at 12:1 thats almost 28hp)

you should gain that across the entire powerband and enjoy a fair amount better gas milage. You will have high thermal efficiency, a good expansion ratio along with flat top pistons. sweet deal.

While you are swapping the heads, polish the piston and combustion chamber- especially any edges/corners. This will help reduce knock.

 

For a truck you really dont want much over 10.1, i would bet you would only gain maybe 10-12 HP with one more point of compression with both tuned to the nuts(because of the weight,light car might be different).Do yourself a favor and take a set of stock (317) have them milled .020 for approx 9.8 compression run 28 degrees timing.It will pull harder than a set of small valved 4.8 heads with to much compression.The 6.0 heads are cheap these days.

 

OK guys i checked the 6.0 and it does have flat top pistons. So its an LQ9 then right? and like how much are the 317's used?

 

go on ebay and you can get a set of 317 heads for like cheap......100 bucks......now if you're wanting to run boost or nx......10.1 is as high as i would go.....i've got a lq4....(dish piston)......round about 9.5:1....just right for 200 shot nx......but with the lq9....cam swap and tb and stall.....work out great......not too much boost (6-8lbs)....nitrous bout a 75-125 wet shot......good luck