Thread: What flywheel when mating a GM small block crate motor to a Muncie 4 speed?

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What flywheel should I use to mate a GM small block crate motor to a Muncie 4 speed. I was told it's an 'old style' Muncie. I'm putting this into my '70 Nova. Thank You! Bill

Spec's on the motor...

It shows the engine as being externally balanced, which probably means it should use a 400SB (externally balanced) flywheel.....but I would sure check with the tech line to be sure. If it doesn't come with a balancer it will also need the corresponding externally balanced balancer.

Then you need to decide what size flywheel you need (153 or 168 tooth) which will be dictated by the bell housing you're using.



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Thank You Mike! I'll call the tech line & see what they say & report back. I didn't think of that. I talked to a mechanic who did this swap but he couldn't remember what flywheel he used. But he did say the diameter of the crankshaft coming out of the rear of the motor was the wrong diameter for a regular old school small block chev flywheel. Bill

From what I see and read about the other mechanic-is it a one or two piece rear seal block??the one piece seal cranks use a smaller diameter hub for the flywheel and you will need an external balanced one-----just use clutch disc with splines for the muncie

Thank you Jerry! It's a 1 piece rear main seal... So that means the crank hub is smaller. So a flywheel for a 400 small block won't fit, right? I need a flywheel with a small hub that's externally balanced... Bill