The Stovebolt Forums Forums The Shop Area Driveline HD clutch

There have been a couple of threads recently discussing the oddball 9-bolt pressure plates and HD clutches that were available on some of the big bolts. Can anyone think of a reason a regular flywheel couldn't be drilled and tapped for the much less expensive and more available 6 bolt clutch cover that's used on the small block V8's from the 60's and beyond that works with the 11" disc? The transmission input spline is the same, and if an accurate drill/tap job is done, it seems that would be an alternative to trying to find the 9 bolt cover, or getting one rebuilt. A dividing head and a Bridgeport mill or a heavy duty drill press should be all that's required to get the hole spacing right. Comments?
Jerry

My clutch is the 9 bolt. I noticed the other day that the flywheel is also drilled and taped for a 6 bolt clutch. I have a 10" rotary table and setting up to do that would not be very hard to do at all. I have a DRO too, so, once you find center of the flywheel it is simply one move and 60 degrees between holes.

I have an 11 inch flywheel that had once been used in a 1953 Corvette that got totalled. It had been drilled and tapped for different pressure plates when I got it. Don't know why, but that's the way it was done. Whatever the story, the holes looked to be all the same. I ended up using a 6 bolt pressure plate for a Chevy V8 and a disc for a Chevy van (I needed a spline that would fit the T5). Once I sorted the throwout bearing and clutch linkage rod length, it was all done.