Won't Shift Into Gear While Running

Makes me think you may have the wrong fork pivot bracket bolted in
the bellhousing. If it is at a different height or angle you would have adjustment
issues. I had this happen on a lakewood that was previously used on a truck before
I used it in a dart. Check fork and throw out bearing length while your in there.
They made more than just the one you need on these parts.
Changing to the correct pivot made it all work together correct for me.
Just something to check that hasn't been mentioned yet?
Brewers site is a good guide to confirm what your car is built with to find a possible mismatch.