SScamaro4

iTrader: (2)

i just bought a ls1 out of a 98 z28 are the heads 853 or 241s an also if the motor supposely has 35to40k on it should the rear main seal be leaking ?

transam69230

iTrader: (49)

First off look at the valve covers and are the bolts in the center or on the perimeter? If they are in the perimeter then you an 853 head for sure. 853s also came with center bolt valve covers as well. The only true way to tell is look on the head for the number. There is no way you have 241s unless someone swapped them on to the block.

SScamaro4

iTrader: (2)

these valve covers arent center bolts i had an ls1 from from 2000 ss the original motor that had 241s i was just wonderin cuz im cammin my car and i dont feel like getting stuck with shitty *** heads that dont flow

02*C5

iTrader: (1)

241s fall in that category. The "shitty *** heads that don't flow" Most if not all will tell you to swap out the 241 to 243s. Take this from some one who fought the battle had my 241s ported polished, milled to the tune of $1200 and now I am running 243s $400.

241s really are not that good of heads Advice is free mistakes tend to cost after a while hence my mistake hopefully will help you save money.

SScamaro4

iTrader: (2)

haha nah i have 243s from my ls6 that came out of a 01 zo6 its just i bent the valves and fucked up with the valves are that whole circle is fucked an i guess i gotta get them fixed aint wastin my time on heads that are **** thanks guys