Re: Ignorance breeds vibration...
I replaced a clutch on a 302 this year and induced a helluva vibration in the process. It started about 2000 rpm and got scary by 4000 rpm. Turned out to be a bad NEW clutch. By bad I mean the pressure plate was out of balance. I don't remember the manufacturer of the clutch but it had a Made in Mexico sticker on it. The way we were able to ID the problem was by removing the pressure plate and disk and reinstalling the tranny without them. There was no vibration without the pressure plate. We exchanged the new clutch for another new clutch that cost about $50 more and haven't had any vibration problems since. What I think is very interesting about this is that NOBODY involved in this had ever heard of a
new pressure plate that had a balance problem. That includes the shop that supplied the clutch, a local driveline shop and a local shop that balances rotating assemblies. It's a lot of work, but you might try running your motor without the clutch because you COULD have just a bad pressure plate. If that's not it I would bite the bullet and pull it all down and take the whole rotating assembly to a balance shop. This is one of those deals where the longest way is actually the shortest way.
\'83 Mustang Hatch, 347, Edel 6025 heads, 2.02 in, 1.60 ex, CC280HR cam
Edel RPM intake, 650 CFM Holly DP Carb, 4.10 Locker rear end, new C4(untested), 12.4 @ 115 in October of 06 with T5