Slipping out of 3 rd on compression

[tbirdtbird]

"The needle bearing cage that was provided in the transmission rebuild kit was too long for the input main shaft and it pressed the input shaft forward a bit which didn't help with the engagement of third gear."

Are you using Ford PN A7063 the main shaft spacer ring? Tom Endy has cautioned about not forgetting this...

Brattons and Snyders show that their shafts, gears, and roller caged bearings are USA made. Possibly others too but I do not have the catalogues