How fast can I spin a 383 with stock 400 rods and still be safe? I want to put an XE 284 in my 383 and I don't want to over rev the motor. The cam is 240/246@ 050. I'm thinking the engine should make power close to 6800rpm.
Dave R.

My brother is running a 383 with the 5.565" 400 rods with aftermarket rod bolts and he takes it to 6000 rpm without any problems.

The real answer is: How heavy are your pistons, and is the rest of the valvetrain up to the stress?

Your pistons "should" be lighter than comparable 400 pistons because of the smaller bore, but I for one would not spin stock 400 rods to 6K when using typical off-the-shelf pistons and pins.

Pistons are forged flat tops. I don't know about the pins.

You wont need to spin that motor past 6000 anyway and like was said already,dont make a habit out of it. Those rods are not real tough so play it safe. :cool: