TRUCKIN

iTrader: (3)

So I have 803 heads. In another thread I was told to get 241 or 243 heads and have them worked and milled. What is the difference between the the two sets? The car is a 98Z. Im just wondering due to wanting to do some work to the car in the future

silverz28camaro

iTrader: (20)

the 241 are basically the same as 853, and your 98 heads, except yours have perimeter valve cover bolts, all others 99 up have center bolts.

If anything get the 243 heads, they are basically the ls6 heads that come on all newer ls2 motors and the 2002 ls6 zo6, but the 2002 z06 head had hollow stem valves so if you find these get'em.

the 243 heads has slightly smaller combustion chamber 64 vs 66, slightly bigger intake port and a D shape exhaust port for better flow.

Either way you will need new center bolt valve covers and coil packs to go with them.

MonmouthCtyLS7

iTrader: (6)

The 241's are a slightly better design...but you wouldnt notice anything from changing them(maybe a few hp). As posted above the 243's are the c5 z06 heads and that swap will generally give you 15hp...Ported 243's seem to be a popular option though.

DANOZ28

iTrader: (1)

your 98's have a different bolt pattern so you may want to check with a sponcor such as texas speed to fix you up. 243's off a vette have the special hollow lightweight exhaust valves. i bought 243 (ls6) cast heads with steel valves from texas speed which ported stage 1 outflow the ls1 heads (ls6 better design). ported stage 1's will probably cost 1k, mine came with ls6 springs, i would upgrade the springs. ls6 springs only good to 570 lift. just my 2 cents ,good luck

TRUCKIN

iTrader: (3)

Thanks guys. This is all for future references for my car. At least I know what to look for now if I swap the heads.