Bought a rebuilt 350, dropped it in my 64 chev.

Bought a rebuilt 350, dropped it in my 64 chev s/side
Runs great. BUT. I can't get the clutch to adjust.
I can see the clutch plate moving when you work the clutch and the peddle feels good. When you try to put it in gear it just grinds
When I tried to adjust the clutch, I ran out of length and added a couple of nuts to the rod to extend the distance, thinking maybe I wasn't applying enough pressure for the clutch plate. This gave me a wider gap in the clutch plate action as the clutch was applied but seem to weaken the clutch peddle action. It doesn't seem to have the mid range release as you depress the clutch. It just feels consistent. When the truck is off. Gears shift fine.
If it's running in neutral, you can't shift into gear (grinds)
If it's in gear and you depress clutch truck lurches forward.
Thanks,

Michael