Monte1984

I got 317 on my lq4.... But I have a set of 243's in the floor and a set of 799 in a junked truck I got..... Is either set of heads better then the 317..... Or not worth the time changing them.....Thanks

silverz28camaro

iTrader: (20)

243's flow the same, but will give more compresion vs your stock heads. about a .8 compression bump i think.

ZONES89RS

iTrader: (25)

Depends on the application, the lower compression allows for less octane, but for performance, the 243/799 wil be better, they are actually a identical casting(243/799), so it is up to what you are doing, i have 317s and will be switching to the 243s.

NemeSS

iTrader: (127)

Can't go wrong with any of those. Sounds like you got all versions at your disposal. I'm partial to 317s since they are cheaper and easier to come by than 243/799
Some of the newest 243/799 have a very smooth chamber compared to the older versions with rough chambers

speedtigger

iTrader: (16)

I would only change them if you have an aftermarket camshaft with a duration of 220 @ .050" or larger. Then, the additional compression would be of benefit.

Paul57

The 243's and the 317's flow very similar. But, the 243's have a smaller combustion chamber.

Monte1984

Well my dad has a junk yard....that's where I got my LQ4.... And was thinking bout changing to the 243's since I got a set....I got the car together bout a mouth ago....so I'm goin to play a little before I change them.....I was just thinking if there's a big HP increase I would go a head and change them....