I'm about to transplant a 70 455 into my 71 GS350 and suppose I should install headers and maybe even an aftermarket intake manifold. What size exhaust is best for all around use... I guess 2.5 all the way. The car is bone stock internally and will stay that way. Any thoughts as to whether it's worth it? This is just a cruiser, not a racer. Thank you for all your advice. TIA Frank
For just cruising stay with stock. You will not see any performance diff without other changes (cam.) You will have less ground clearance and more noise. Make sure you can get a good sharp tune. I think the most bang for your buck is to upgrade the ignition system. I could not believe how much better my car ran with the following changes; Upgraded alternator to 12si to get 14v (do not use 1wire system, use 3 wire) Do not waste money for the rest of the system unless you are getting 13.8 to 14.2 volts. Rebuilt stock distributor with Crane led trigger, recurved for 18* mechanical (run 14* initial) all in at 2500 rpm. Used MSD HEI style cap. Crane Hi-6 box with Crane coil.
The Edelbrock B4B with some Headers and 2.5 in. exhaust would work very nice in a stock '70 455. Ignition upgrade is also highly recommended. At least an HEI unit. But for better results and simple install, I have heard a lot of good stuff about the Pertronix points conversion kit. Check Summit or Jeg's or somewhere and do a little research. Good luck.:TU:
