Which head for a LQ4? 243,l92,Prc?
Which head for a LQ4? 243,l92,Prc? Im looking into do a head and cam swap on my Lq4. But not sure which route to go with the heads. Whats your guys opinion? My current setup is 03 lq4, ls6 intake, ported tb, headers, finishing a t56 swap now, 12 bolt 3.55s
Budget is a huge factor. 243s can be had for $400 and would bump the compression up. L92s are going to require new valvetrain and intake, but the heads aren't that expensive. Prcs are gonna cost some coin but you can reuse your valvetrain and intake. All comes down to budget, cam choice, and what you want out of the car
The Chevelle is not exactly a light car, the 3.55s are really more of a mid-
street gear, and the LQ4 having dished pistons (lower comp.); I'd shy away
from the L92 heads. They flow real well but have a large IN. valve and runner
which prefers a larger bore/engine in order to keep port speed elevated. They
also have a larger chamber which would have to be milled considerably in
order to get your compression to 10 ish. That being said I'd look at some CNC
5.3 (PRC) heads which at around 60cc chambers will give you 10.75 comp to
match a healthy 230/234 sized cam. If budget doesn't allow for that, you
could search the Corvette Forums for a used set of 243 castings ($400-$500)
get a valve job/mill .025"-.030"/install a PRC or Lunati dual spring kit and have
someone spec a cam for ya. This route would also get your comp. up where
you need it to make good strong power throughout the entire rpm range.
http://www.tickperformance.com/tick-...1-ls6-engines/
street gear, and the LQ4 having dished pistons (lower comp.); I'd shy away
from the L92 heads. They flow real well but have a large IN. valve and runner
which prefers a larger bore/engine in order to keep port speed elevated. They
also have a larger chamber which would have to be milled considerably in
order to get your compression to 10 ish. That being said I'd look at some CNC
5.3 (PRC) heads which at around 60cc chambers will give you 10.75 comp to
match a healthy 230/234 sized cam. If budget doesn't allow for that, you
could search the Corvette Forums for a used set of 243 castings ($400-$500)
get a valve job/mill .025"-.030"/install a PRC or Lunati dual spring kit and have
someone spec a cam for ya. This route would also get your comp. up where
you need it to make good strong power throughout the entire rpm range.
http://www.tickperformance.com/tick-...1-ls6-engines/
We all have a budget, but if i can get a better head then another for a few more bucks than thats what ill do. I know i would have to change my intake with the l92s but didnt know about the valve train. I know the 3.55s are holding me back a lil but i planned switching to a 3.90 gear. How much better is the prc head then the 243?
We all have a budget, but if i can get a better head then another for a few more bucks than thats what ill do. I know i would have to change my intake with the l92s but didnt know about the valve train. I know the 3.55s are holding me back a lil but i planned switching to a 3.90 gear. How much better is the prc head then the 243?
having 2 overdrive ratios will still knock it in half for freeway drivability.
PRC heads have either a stage 1 or 2.5 and each will offer 30-45 cfm more
or roughly 25 rwhp more than a production as cast 243. If you're fortunate
to find a set of ZO6 Vette 243s that would have the lightweight hollow-stem
valves which work real nice to control the valvetrain at high rpms. The $$$$$
savings from going this route would offset the cost of the cam...FWIW
The 3.90 would work nice, but most suggest a 4.10 with the 6 speed as
having 2 overdrive ratios will still knock it in half for freeway drivability.
PRC heads have either a stage 1 or 2.5 and each will offer 30-45 cfm more
or roughly 25 rwhp more than a production as cast 243. If you're fortunate
to find a set of ZO6 Vette 243s that would have the lightweight hollow-stem
valves which work real nice to control the valvetrain at high rpms. The $$$$$
savings from going this route would offset the cost of the cam...FWIW
having 2 overdrive ratios will still knock it in half for freeway drivability.
PRC heads have either a stage 1 or 2.5 and each will offer 30-45 cfm more
or roughly 25 rwhp more than a production as cast 243. If you're fortunate
to find a set of ZO6 Vette 243s that would have the lightweight hollow-stem
valves which work real nice to control the valvetrain at high rpms. The $$$$$
savings from going this route would offset the cost of the cam...FWIW
Im in the same boat, I have a 2007 LQ4 in a 1980 Trans am Edelbrock headers, LS6 intake Ported TB, but I have a 4L80E and 3.42 gears. Just picked up a EPS 226/234 cam and some 243 heads. I decided to go with AI for my heads, everyone here loves them and they making 40 to 55 RWHP They have some articles on their website. Good luck with your choice. I guess you lose alot of torque with l92 heads from what I have read....
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Im in the same boat, I have a 2007 LQ4 in a 1980 Trans am Edelbrock headers, LS6 intake Ported TB, but I have a 4L80E and 3.42 gears. Just picked up a EPS 226/234 cam and some 243 heads. I decided to go with AI for my heads, everyone here loves them and they making 40 to 55 RWHP They have some articles on their website. Good luck with your choice. I guess you lose alot of torque with l92 heads from what I have read....
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Verdad Gallardo Yes I will have i dynoed and tuned at new era next spring. Because of the 4L80E and the Yank ss3600 coverter....I hoping for 400 RWHP, but I will take that 4L80E over a 4L60E anytime...I hate fixing the samething over and over again.
