The Stovebolt Site Forums The Shop Area Engine Shop externally balanced engine -vs- internally balanced

The flywheel and the harmonic balancer do the final balancing on the 400 motor. You will need to use the 400 balancer and you will need to purchase a flywheel for the 400 small block motor. you will need to purchase an aftermarket clutch and pressure plate combination most likely from someone like CenterForce or Hays since you are going to have to purchase one of their flywheels.You will need to purchase a 168 tooth version if you plan on using the 400 starter( blolts to the block). If buy chance the starter you plan on using is the type that bolts to the bellhousing then will will need to purchase a 153 tooth flywheel for the small block 400. I know Summit carries the Hays flywheels with either tooth combination externally balanced for about $225.00. There were maybe few Chevy/GMC pickups manufactured about 1970 with manual shift trans. on the smallblock 400 but I believe all the passenger car were automatics.I think it would be a rare find to come up with a factory 400 flywheel. Let me know if you have any other questions.Paul