OD auto question

[Clelan]

Forgive me if this has been asked before, but, Will an A-518 OD auto last in my 74 360 Duster. I want 4.10 gears and an OD auto.

How much power will it handle?

 

[fishy68]

Yes but not easily. The transmission tunnel is too small on A-bodies and will have to be cut out and be made larger to clear the larger overdrive unit on the A518. I'm not an A518 guru so I can't say just how much power they can take but I've always heard their weak point is the OD unit and somewhere in the neighborhood of 350 HP is all they can handle stock but don't quote me on that for sure. If you really wan't overdrive consider one of gear vendors units. I don't think you have to cut your floor for them to clear and they will handle more power and they bolt right to the back of a 727.

 

[Clelan]

Does anyone know how much modification would be neccesary to my trans tunnel. As long as it would not look bad from inside, I would be Ok with this.

I have heard that the geer vendors unit is very expensive so I wanted to check the other option out first.

 

[fishy68]

I know where your coming from on the money situation. I can't say how much modification is necessary since I haven't done one myself but if you have the cutting and welding equipment go for it. I have also read that the crossmember will need modifying. That part may be more tedious than the floor pan mod. As far as it looking bad from inside I doubt that would be any problem if done correctly. Just don't do a hatchet job on it and make things lumpy. If you have a stock console you may run into problems there also because the rear will be raised some and it may not sit correctly. Also the carpet may not lay correctly anymore.

Again since I have not done a mod such as this dont take my words as gosple. These are just things to think of. Some of them I have read on boards though such as the tunnel mod and crossmember mod is required. The others are what I think may be required.

 

[OlDuster]

We installed a 518/46RH tranny in my '68 Dart. We had to build a new tranny mount and expand the floorboards. I did not have a digital camera when we did it. I now have a scanner. I can try to locate the pics and send them to you if you are serious about this modification.

I have a bench seat and stock carpeting. My seat still moves on the runners and the carpet fits fine. All you are doing is keeping the same size of "hump" in the floorpan for an additional 5" towards the rear of the car.

 

[superdart]

So no hacking of the crossmember is required? Hmmm.........

I had thought about an A-500 in my Dart, but understood it needed the same mods as the A-518. My motor is pretty mild, and I think an OD with 4:10 gears in the axle would be great.

For now, my plan is to build my 904, and put 3.55s in the rear end (currently 2.45s). This information, however, brings up possibilities.....

 

[Clelan]

We installed a 518/46RH tranny in my '68 Dart. We had to build a new tranny mount and expand the floorboards. I did not have a digital camera when we did it. I now have a scanner. I can try to locate the pics and send them to you if you are serious about this modification.

I have a bench seat and stock carpeting. My seat still moves on the runners and the carpet fits fine. All you are doing is keeping the same size of "hump" in the floorpan for an additional 5" towards the rear of the car.

If you could get me some pics that would be great. I really think this mod will give me a real performance boost while retaining drivability, as long as the trans will hold up.