I ran a OD behind a stroked 340 with 410 gears. It was great for gas millage and burn outs. Just don't make the mistake of shifting under power, they wont take it. I broke two of them going from 3rd to 4th. Got great gas millage ,Drove from LR Ark to the nats with 340 6pk,4spOD, 410 gears and got decent gas millage. I would vote go for it.
racerx23 My 2 cents. I have a demon with a 426 wedge that was backed by the od trans.the car ran mid 12's with no trans problem, I personally like the trans and have no issues. As a matter of fact I just put one behind my stock demon and almost doubled the mileage.
marksmopar1 I had a regular 4 speed behind a hot 360 in a 73 Dart Sport...I changed to a OD 4 speed and loved it! Great street power between lights, and highway cruise RPM was noticable.
As for strength, work fine no issues! Drag out the 1 st gear and I would skip 2nd straight to 3rd...lol 2 speed with OD on the Highway! I would do it again...was 3:23 sure grip by the way
Walker434 FABO member Badlilred79 has a 4 speed OD in his yellow 70 duster with a blown 340 in it. It has stood up to a lot of abuse for years.
I can't say if it has been beefed up internally but I know I have taken a wild ride in that car and the transmission has held up.
I also know he doesn't power shift into 4th. Hard throttle is 1-3 and 4th gear is just for cruising.
teringer I also used one od from a 78 aspen in a 450 hp stockcar 30 laps 2 times a week /1/2 mile oval ,strength was not a issue ,and the 8 1/4 rear built proof ,lost 10 t0 20 tires wheels from a little rubbing and never had axle issues with stock parts while the others brand wood snap a axle just hitting a bump. my only problem with them is you just cant shift them as quickly with the wide gear ratio ,but I will trade that for 28 miles to the gallon with a nice build 318 any day.
YY1 My O/D is living just fine behind a mildly build 440 in a full size truck.
It's super fun to drive, despite the 3.09 first being a bit short, and need to watch shifting to 3rd too soon.
(lots of time spent in that second)
Serious power shifting into ANY overdrive gear is probably not a great idea anyway.
At that point you're likely up pretty good in RPM.
