Performer or Performer RPM
I currently have a 69 428 in a 65 GTO. It is a YH code 4 bolt main that has been bored 30 over. It has a cast crank, probably the original looking at the casting number, heat treated rods out of a 62 421SD, and TRW forged pistons. It has 72cc Edelbrock Performer RPM heads and an Ultradyne 280/288 H12 cam with a lobe separation of 110 degrees, 223/231 duration @ 50 and .463/.485 lift with 1.5 rockers; however, the engine has 1.65 rockers so the lift is .510/.534. Currently it has an Edelbrock P4B square bore intake (the older style with the smaller runners) and an Edelbrock Thunder AVS 800 carburetor. I am considering replacing the intake but I cannot make up my mind between the Edelbrock Performer and the Edelbrock Performer RPM. This car is not for the track and most of its use will be weekend cruises, car shows, and maybe a couple of cross country muscle car tours, hopefully. Oh, and the occasional full throttle stop light romp, we must play every now and then and my brother-in-law has a 71 454 SS Chevelle that I love to embarrass. The cam's RPM is rated from 1500 to 5800, or 2000 to 6500 depending on which web site you look at. I know the Performer intake is for low end power and is rated from idle to 5500 while the RPM is rated from 1500 to 6500. Would I be better staying with the P4B intake, getting the Performer intake to match the type of driving this engine will see most of the time, or getting the RPM intake which is a better match for the cam's operating RPM? When you drive the car you can really feel when the cam starts to become effective. Around 1700 the car has a lot more power. It is no slouch below 1700 but it is definitely stronger above 1700. One person advised to use the Performer Intake with a 1" closed spacer so you have the low end power of the Performer but the spacer would help add some high end power to better match the cam.
I know just enough about this stuff to make myself dangerous, but not enough to be able to make great decisions that won't result in wasted money. So any help or advice from the experts out there would be greatly appreciated.
Someday, money permitting, I would love to put a tri-power setup on this car. But that option is cost prohibited as of this time.