In case you missed this.........

Quote:

Unless you have one of the really rare late 1971 blocks that where cast for the 400 motors you need to be very careful on tuning, no detonation Most of the 383 blocks had thin main webs like most RB blocks do



Go to the 440Source website and look at the B/RB casting pic's, specifically the mainwebs.

A 440Source kit still needs to be thoroughly inspected by your builder. MuscleMotors will do all of that for you.

R.I.P.- Gary "Coop" Davis 02/09/68-05/13/04