LS1 head porting

[The_Humbler]

Can 853's be made to accept 1.61 exhaust valves?


Also, are the Z06 valves the same length, or can they be made to work on a "standard" LS1 type head?

[Fast01]

I don't believe the 853's will accept a 1.61" valve, the seats are not big enough. The LS6 valves from the 243 heads are longer (can't remember by how much) than the 853/241 valves to compensate for the smaller base circle cam used in the LS6 engine. GM decided to go that route instead of altering pushrod length.

[Shawn MacAnanny]

I wouldnt use the z06 sodium filled valves with an aftermarket camshaft anyway as their 'hollow' stems were not really designed for aftermarket valve springs and i have read several horror stories of them breaking.