I have put 1980 Dodge Aspen running gear into a 1937 Dodge D5 Sedan.

It is a slant 6 with a torquflight transmission. What transmission fluid currently available is best for this transmission?

Will the new Mopar ATF+3 work? Would it work better and enable the transmission to last longer then the original trans fluid?

 

I have a 1979 dodge aspen with a 225 super six or slant six use dextron type pennsoil has worked great for me!

 

Sure, it wil work just fine.

If you want superior fluid, go with a synthetic.

 

Moe in Wichita,KS. For long trans life put in 2 qts of rear end grease. it will shift a little tighter. do this only on the older tourqflites. it may or may notbe ok on the newer trans. i have put one qt in my 1999 dakota v 6 so far so good. this is an old drag racers trick