M-21 Clutch / Flywheel Recommendations?

[point-five-o]

I’m in the process of a powertrain overhaul on my ’72 Chevelle, which includes a 450-HP 383 in place of the factory 350, and an M-21 4-speed in place of the factory 3-speed, and I was wondering if anyone had any clutch assembly and/or flywheel recommendations? This car will see a bit of everything when done—street, autocross, road racing, etc. (probably no drag) . . . do I need an SFI approved flywheel, or can I get away with a standard unit? There seem to be quite a few clutch’s that are rated for my engine’s output, but I don’t have any experience with any of them, so any direction would be very appreciated!

[Gitter Dun]

For 450 HP the Center Force dual friction will be fine. The diaphram style of the Center Force pressure plate is easy on the leg and the holding force is more than adequate. 3 prong pressure plates tend to be a little tougher on the leg and thats no fun when in traffic. Flywheels are a matter of preference. Aluminum flyweels will allow you to spin the rpm's alot quicker but they cost a bit more. If you are on a budget, a used OEM flywheel will be fine. I road raced with my OEM flywheel for years before I installed my aluminum one. I prefer the 153 tooth flywheel over the 168 but either one should be fine.

[point-five-o]

Thanks for your input. Does the tooth count on the flywheel dictate the diameter of the clutch you're able to run? If the aluminum flywheel makes a noticeable difference, then I may just go that route.

[Gitter Dun]

Yes, with a 153 tooth flywheel you will use a 10.5" clutch, 168 tooth is 11". One thing I forgot to mention, be sure to match your starter to your flywheel.

[chicane67]

GM sells a stock iron wheel that weights 15 lbs for a good price.

You get the performance of an alloy wheel for an affordable price. They have them on Scoggin Dickeys website...

[TT302Z28]

I have always liked the Hays flywheels and just like Gaetano said, the Center Force clutches are good. I'm running an 11" in my 68 with the 496 and have no issues.

[point-five-o]

Thanks for all the advice, guys. Very helpful!

[Oakesters]

GM sells a stock iron wheel that weights 15 lbs for a good price.

You get the performance of an alloy wheel for an affordable price. They have them on Scoggin Dickeys website...

GM Performance 14085720
http://www.summitracing.com/search/?...85720%20&dds=1