We use MOPAR brand manual trans. lubricant NV3500.part #4874464.MOPAR also sells a synthetic fluid -NV4500.The NV3500 goes for about $16 bucks a qt.check with your local dealer

-1967 Plymouth Satellite #3555
446 cid on E-85
best 1/4 et 10.577 @ 127.58
best 1/8 et 6.722 @ 100.68
best 60ft. 1.419