??????

[timracer44]

need some feed back. im running 2550 bottom end with the 620 roller cam, 500 cfm holley. my problem is i cant get no more than 6800 rpm. i checked the tranny ratio it is 2.14, rearend ratio 3.45. I have tried everything and still no more than 6800 rpm. i was recently told to switch to a GM HEI module. anybody with some info would be greatly appreciated.

[Milford Motorsports]

A TFI Ford distributor will do anything the HEI will do.Have you checked the carb completely,possible clogged jet,passageway?What type of intake are you running,any possible restrictions in air flow,carb spacer,intake gasket,air cleaner?Lastly check your valve springs,possible coil bind,weak,improperly installed?620 lift requires everything to be spot on or it will not function properly.Good luck!

[drtlvr]

The one I had would lose power at 6800 too. I think the heads we were trying were cut too much for a 2500.

[crazyhorse]

is cam timing straight up or advanced?