Valve Length - 243 Castings
09-08-2006, 08:54 AM
#1
Valve Length - 243 Castings I recently bought a set of 2006 Trailblazer heads off of Ebay (243 castings) to use on my 2001 Trans Am. I'm thinking of putting in a 02-04 Z06 cam for now (cheaper, no tuning required) and I'm not sure if the valves are the same length as LS6 valves, or standard LS1. The reason I ask is that it will determine whether I need push-rods in 7.4 or 7.425 length to compensate for the Z06 base circle reduction. Is it worth buying the LS6 intake and exhaust valves? thanks!
brian
brian
09-08-2006, 10:38 AM
#2
First, I wouldn't waste the time or expense of putting a cam in that's as small as the zo6 cam (unless FI). At least go to a TR224/224. It's not that bad to tune. If you need to save up first for tuning, then I'd do that b/c your probably going to need a tune after the new heads are on anyways.
You mostly likely have the LS2 valves on your 243's so they're perfectly fine to keep. If you don't mill the heads (which you should!) and you have the zo6 cam, I think that 7.25 would be a good length. Otherwise, most cams have smaller base circle than stock and if you decide to mill a little (.010 or so) then it would probably be closer to 7.4 to have around .080 preload on ur lifters. .080 would be a good preload if u have stock lifters too btw. You should get a PR length checker and be sure though once ur in there.
The zo6 cam has a smaller base circle than LS1's?
You mostly likely have the LS2 valves on your 243's so they're perfectly fine to keep. If you don't mill the heads (which you should!) and you have the zo6 cam, I think that 7.25 would be a good length. Otherwise, most cams have smaller base circle than stock and if you decide to mill a little (.010 or so) then it would probably be closer to 7.4 to have around .080 preload on ur lifters. .080 would be a good preload if u have stock lifters too btw. You should get a PR length checker and be sure though once ur in there.
The zo6 cam has a smaller base circle than LS1's?