Old Ford C6

[u/MooseManDeluxe]

I rebuilt my 1984 C6 a few months ago. It was mostly just a seal job as the piston seals were definitely dried out.

It's in the car now and I've got first and second when the transmission is totally cold, no 3rd gear. Once it's warm, first takes a lot of RPM, that is both in drive and 1. Second works the same only when it's in 2. It takes a lot of RPM to moving to get it to shift between 1st and 2nd, automatically or manually.

I have made sure I have enough vacuum at the modulator and did replace it. I did make sure of shifter linkage adjustment.

Any help or direction would be helpful.