black4.8

iTrader: (1)

i ran 15# on 93 gas and 16 degrees timing before i added meth. never saw any knock even w/ high iat on dyno. if you want to be extra safe run 12# and less timing, low 11's a/f .

TIM Z

iTrader: (12)

Anyway you can get some 110 to throw in the tank?

I ve been running 110 and 93 mix for piece of mind at 14 psi.

Been thinking about meth myself and am going to order a kit soon.

1SloLQ9

Try changing your oil if its at all old, My 05 5.3 lm7 I believe I knicked a bearing swapping cams, truck used to have 50lbs at idle cold and about 40 hot idle with 5w30, i swapped cam and added s/c and I noticed my oil pressure would be more like 35-40 cold idle and as low as 15 hot. no ticks or funny noises, I dropped the oil since it had about 4k on it, tossed in some 10w30 pennzoil and now it idles at 45-50 cold, 25-30 hot idle and 45 cruiising where i could barely break 25 cruising. oil must have been broken down. i know its still low for a 5.3 I will just have to wait and put in a 6.0 or a l33 before i solve the lower oil pressure issue completely..

smokeshow

iTrader: (16)

The 4.8 also has much lower compression. Older trucks were 9.1:1 I believe. My 2007 4.8 was 9.0:1.

Beatdown Z

iTrader: (18)

That's ridiculous. Unless it was audible, i would have just desensitized my knock sensors a little bit.

Keep your IAT's and ECT's down and be sure to run a four corner cylinder head vent pipe and you should be fine.

cjg454ss

iTrader: (27)

every car is different. some like timing and some dont. most people over fuel the motor and over time it. i dont run the vent pipe on my camaro and that makes 1500hp, at the tires

Denali08

Can you explain how u did that?

slow67

iTrader: (2)

I'm pretty sure the gen III 4.8s are the same as 5.3Ls, 9.5:1, and the gen IVs are 9.1:1

bud8fan

iTrader: (9)

i have learned that each engine is diffrent....i have run 26* of timing and 10 lb of boost and not had an issue and another engine would only muster 19* at 10 lbs....never any lower thou...this is in this hot south texas heat also....basically stock engines with upgraded cam,springs and push rods only.

1969x11

iTrader: (38)

Older trucks and ls1's had the 4 corner vent pipe.