C6 linkage

I bought a C6 a while back, and put in a shift kit. I'm pretty sure I put the valve body back in right, and how the shifter linkage engages it. But I'm only getting three positions to switch through when I push the rod through the gears. I can't remember if it was like this before. Shouldn't I be getting all six detents? Or does the thing need to be installed and spinning?
One more question, does anyone know if my '67 C4 linkage hook right up to this trans with some adjustment? the C6 is from a '76 Lincoln and will be behind a 460 - with the crites motor/trans mounts and headers.
Thanks,
for me, transmissions still fall under black magic

67 coupe, 289