403 build discussion thread
403 build discussion thread Im in the process of building a 403 for my camaro. I've got the rotating assembly and I'm waiting on the block to come in so I can take it to the machine shop for the block to be machined. Here is the specs of what I've got put together so far parts wise...
4" Scat Crank
Eagle H-beam 6.125" w/ arp2000 bolts
4.005" Wiseco Nitrous pistons with -3cc vr and a 1.110 compression height
Hellfire Rings
ACL Race Bearings
TREX v2 Cam
Eric Carey ported LS6 cylinder heads... (graduated from SAM a few years back)
Fast 90/90
Now for the discussion. I've been looking into different cylinder heads because the LS6 heads I have are a mild intake and exhaust port job with a nice valve job that was blended into the stock combustion chamber. I don't think these heads will perform as well as AFR, TFS, ETP etc etc. With that said I don't really want to drop 2500 for a set of heads but my ultimate goal is to break the 500whp mark. I've been considering switching and going with the PRC CNC LS3 heads since they put up some awsome flow numbers but with those heads will I have the velocity to keep my midrange? Also the TREX cam wouldnt be ideal for the LS3 style head either or would it? I'm also not dead set on the TREXv2 cam. I did however see a 402 thread where a guy used AFR 205's with a 242/242 .610/.610 114lsa and he was laying down right around 500 and that cam is pretty similar to the TREXv2. I'm basically needing some reasureance that I'm on the right path and not putting together a combo that wont work. The motor will be mostly used for drag racing and will get a good 200-250 shot every once in a while but not an every weekend deal. It will be driven on the street more than the track and is a 6spd car. With that said I know the AFR 205's will make crazy throttle response and low end torque but is it really needed since the low end will already be emphasized by the stroker bottom end itself? Will the AFR 225's benifit me more where I will be in the upper RPM's more for drag racing and help out the Nitrous aspect? Are there any other nice cathedral port heads to consider that are reasonable. Im thinking I need to keep the valve angle at 15* as well cause that is what the valve relief on the piston is setup for. I like the looks of the new PRC 237cc runner heads as well but I need some real world results to be able to compare them to the AFR's. Just post up your thoughts on my randomness here.... thanks
4" Scat Crank
Eagle H-beam 6.125" w/ arp2000 bolts
4.005" Wiseco Nitrous pistons with -3cc vr and a 1.110 compression height
Hellfire Rings
ACL Race Bearings
TREX v2 Cam
Eric Carey ported LS6 cylinder heads... (graduated from SAM a few years back)
Fast 90/90
Now for the discussion. I've been looking into different cylinder heads because the LS6 heads I have are a mild intake and exhaust port job with a nice valve job that was blended into the stock combustion chamber. I don't think these heads will perform as well as AFR, TFS, ETP etc etc. With that said I don't really want to drop 2500 for a set of heads but my ultimate goal is to break the 500whp mark. I've been considering switching and going with the PRC CNC LS3 heads since they put up some awsome flow numbers but with those heads will I have the velocity to keep my midrange? Also the TREX cam wouldnt be ideal for the LS3 style head either or would it? I'm also not dead set on the TREXv2 cam. I did however see a 402 thread where a guy used AFR 205's with a 242/242 .610/.610 114lsa and he was laying down right around 500 and that cam is pretty similar to the TREXv2. I'm basically needing some reasureance that I'm on the right path and not putting together a combo that wont work. The motor will be mostly used for drag racing and will get a good 200-250 shot every once in a while but not an every weekend deal. It will be driven on the street more than the track and is a 6spd car. With that said I know the AFR 205's will make crazy throttle response and low end torque but is it really needed since the low end will already be emphasized by the stroker bottom end itself? Will the AFR 225's benifit me more where I will be in the upper RPM's more for drag racing and help out the Nitrous aspect? Are there any other nice cathedral port heads to consider that are reasonable. Im thinking I need to keep the valve angle at 15* as well cause that is what the valve relief on the piston is setup for. I like the looks of the new PRC 237cc runner heads as well but I need some real world results to be able to compare them to the AFR's. Just post up your thoughts on my randomness here.... thanks
The guys at ECS made 600 RWHP with our LS6 Stg 3 heads on a 440 cu in N/A engine in 2004, you might consider getting those done up right also.
If you already have a Fast intake, then I would stick with a cathedral style head, you will make power easier.
If you don't have the Fast, then the L92/LS3 stuff will make good power cheaper.
If you already have a Fast intake, then I would stick with a cathedral style head, you will make power easier.
If you don't have the Fast, then the L92/LS3 stuff will make good power cheaper.
I hate to bump this thread back up but I've learned a ton in the last 2 year's and wanted to say that I got my 403 up and running and decided on TFS235 heads from TEA and so far the results have absolutely killed all my goals!
'00 Z28 M6 3475lb
10.37@132 NA
9.64@143 150 shot
I'd like to thank Brian Tooley for a huge amount of knowledge that has helped thus far!
'00 Z28 M6 3475lb
10.37@132 NA
9.64@143 150 shot
I'd like to thank Brian Tooley for a huge amount of knowledge that has helped thus far!
