oem 5 speed auto swap??

[74valiant]

as im driving across the u.s. and seeing 75 mph speed limits, i am realizing that having an overdrive would be kinda nice to drop down the rpm and keep the engine cool at higher speed. my question is, has anyone done a 5 speed auto swap with a trans from another stock mopar?? i have a 318 in my 74

 

[70dart]

I think there are a few members on here who have done it. I am a long ways from that stage yet!

 

[damnimcooltom]

I wish my Hemi Ram didn't have a 5-speed auto. It's a chunk. I'd really like the 4-speed auto out of my 98 360 Ram instead.

 

[dgc333]

I believe you would have to do tunnel surgery to make it fit and would need to rig a drive train computer to make it function. Tunnel surgery would also apply to the A500/42RH or A518/46RH 4 speed auto overdrives but a simple switch could be used to activate the overdrive or if you wanted to be more sophisticated there are controllers available that fit inbetween the speedo cable and the tranny that will lock the torque converter and shift into OD. The 4 speed overdrive swap has been done a lot and other than opening up the tunnel to make room for the OD unit on the back of an otherwise 904/727 case its pretty straight forward.

A buddy of mine put an A518 behind a 340 6-pak motor in his 67 Barracuda with 3.9 gears and it works real well.