Hey Red,
I read somewhere that 600 lbs is enough force to hold a tool in an R8 collet.
So far I've found these cheap
Bimba's at Surplus Center that put out 440 lbs.
With leverage, it should work just fine. At only $3.95, it's worth experimenting with.
Probably get a few just to have them.
The cam and lever only needs to move the collet about 1/8 inch I figure.
Later Hoss
http://www.hossmachine.com