Seagram's 72

iTrader: (2)

I currently have an LQ4 factory shortblock with 243 heads on it. I was offered a good deal on a factory LQ9 shortblock. What would my resulting compression be with an LQ9 and 243 heads, and would it be too high for pump gas? Thanks

masterz28

iTrader: (8)

Compression will be excellent, 11:1. And not too much for pump, I might be wrong but you have to be around twelve to one to start worrying about race gas lol.

Bumpers

iTrader: (10)

What he said.. It should be right at 11to one if you use a stock headgasket. And will be fine with 91or 93 octane I have heard ppl say over 11.5 to one is where you start running into problems on pump gas but no real experience there.

Whiteaw57

iTrader: (2)

10.2:1 is where it starts on a non computer controlled locked out timing engine with iron heads. these LS motors are a thing of beauty between the computer controlled timing the aluminum heads and chevy magic they can get up to about 11.5 sometimes 12:1 static with a big cam before you have the first issue. sounds like a cool build, good luck

Seagram's 72

iTrader: (2)

I am running carb, but think I should be fine @ 11:1, thanks!