is it worth it?

[PitRow]

When I first started out in photography I bought some used pentax gear from a friend of my dad's that had a studio and was getting rid of some of his older stuff. I still have all of it collecting dust in my closet. Most of the lenses are just run of the mill standard zooms that I have equivalent of for my current canon (Rebel XT/350D), except one. It is a tokina 400mm 5.6 SD lens, in Pentax-Ka mount.

I'm wondering if it's worthwhile to try to get an adapter for it to use on my canon. I realize it's not a super fast lens, but the 400mm reach would be nice sometimes, especially with the 1.6 conversion.

The lens is the one shown here:
http://www.tbray.org/ongoing/When/200x/ ... L-400-f5.6

I've been doing some searching online and it seems that it maybe possible to buy a cheap adapter for this lens to fit my camera, however it won't work on full-frame or 1.3 camera bodies due to the aperture lever clearance with the mirror.

Does anyone know if the cheap Pentax-K adapters will work with this lens, or would I need to get one of the more expensive "AF confirm" adapters or something totally different.

Thanks!