Thread: Chevy 402 BBC Ignition Issues

Tweet

I have a 72 C20 Big Block truck complete with the 3.54 Dana 60 Rear end. I just got the motor rebuilt, and it runs great except for a vibration in the rpm range of 1750-2000 rpms. The motor runs smooth before and after that, I talked to the machine shop the did the work, and they said it most likely ignition related. Any Ideas from you guys out there.

Oh and it does have a mild RV cam in it, this is my daily driver/work truck!

Any insight would be greatly appreciated.

I don't see where a vibration would be ignition related.... Is it a vibration or is the engine just stumbling a bit?????

I would say more of a stumble than vibration. Its like the motor is almost missing on a cylinder or 2. Some more info on the motor, it has autolite platinum spark plugs gapped at 40, msd 8.5 mm super conductor wires(new), hei distributor with msd cap coil and rotor. Although the cap coil and rotor are all new, the distributor itself is from an 82 El Camino.

Some other people I talked to say it could be the carburetor, the carb thats on there is the Edelbrok 1411, 750 cfm jetted for a big block, again it is still new.