Keith,
The ones I use are maximum effort. I promise that with 470 lbs on the seat and 1250 lbs open there is no need for a rev-kit. lol.
He may also havea full body lifter I have not tried to buy any.
To tell the truth I do not use rev-kits. My hydraulic roller engines rev to 6,900 rpm and might go higer if we tried. No need in trying becuase for the type of engines those are that is enough for a shift point.
I have recently toyed in my head with the rev-kit though. I have not used one since I was a kid when good springs were not avaliable. I have read some of Joe Sherman's postings about them, and I just might try one out in the fairly near future.
Ed