I traded for a 65 mustang. The previous owner had swapped the i6/3sp to a late 70's truck 302/C4 ( low to mid size cam) with a B&M shifter. The motor was completely rebuilt as well as the transmission but it was a 6 yr process. It was only driven 10 miles since installed and traded. Some times it will not go in reverse and when i put it in drive it will shift 1st to 2nd to 3rd for about 3 blocks then it kicks out of gear. from there on it will go 1st to 2nd to out of gear.
i have noticed if i park it on a hill it will leak a little. The fluid was a touch low so i added about a 1/3 of a quart and it seemed to help the reverse issue.
i took it to a local trans shop and he didn't have time to look at it but said every time he has ran into that it was a internal problem. I added a quart of fluid and it was holding 3rd a little better. so I added a second quart and it stayed in 3rd even better and when it kicked out I'd let off and it was wanting to shift back in.
I have noticed that the metal vacuum line from the fire wall area to the side of the trans is a small diameter.
Could the wrong dipstick been installed during the swap, if so how could i tell the correct amount of fluid?
I have a larger vacuum line to install when it cools down this evening.