So I acquired a 360/380HP Magnum Crate Engine with 200 miles on it (was on a show car). This is destined for my 90 Dodge Dakota Convertible swap. I've just found a 78 Rebuilt transmission with 1000 miles on it from a Dodge Sportsman Motorhome. I've been reading about the variations in tail shaft lengths and the bolt on vs slip yoke of some motorhomes, so I'm not sure if this is a feasible swap. I'm attaching two pictures. It seems that the tailshaft is normal length. I can also tell from the spline that it's a non-lockup transmission. Is that suitable for a street/strip weekend truck? Also, no overdrive, although I see one electrical connection so I'm wondering what that's for? Neutral Safety Switch perhaps? I'm guessing it looks like a 2 wire connection, so no backup lights....Does the 90 dakota use the backup from the transmission or shifter?

Looking at the pictures, can anyone provide additional info and whether it's a suitable candidate for my needs.

Specific concerns:

1) Tail shaft of 78 727 will work...From what I can gather if it's a standard 18" TS, then there's a 1" difference between A727 and A518 mounting locations. Is that an issue or is there enough play on the cross member?

2) Non lockup and no overdrive....Ok on a mostly weekend street/strip/cruise-in truck

3) Slip vs Bolt on Yoke

4) Backup lights (looks like only two prong connection to me)

Thanks


http://i195.photobucket.com/albums/z...ps65387d07.jpg

http://i195.photobucket.com/albums/z...ps13db04ae.jpg

 

crickets....

So, I'm rethinking. I have a decent A500 which I know many racers use for its lightweight spinning assembly. I also know that a stock A500 won't hold up to the 360. So, what's required to beef up an A500?

Would a kit like this from HughesPerformance do the trick?

"Hughes Performance Race Products has become the leader in many areas . . . Here is just one more to add to the list. This Premium Race Kit features Kolene¨ steels, "Red" Alto® race frictions, and a Kevlar lined race band. With these items highlighting this box kit, your performance will never be the same."

Kit is about $450 which would be the same I'd spend on a decent 727/A518 after putting a shift kit in it.

 

We have been using the A500 OD in our 70's Cordobas for years and they have held up pretty good. When we first put them in everybody was pretty leery. That way you keep the lock up and the OD.

 

Well, answered one question on the 727 in the picture...That connection is for trans temp/level indicator that was used in some vans in the 76 to 78 era. If I go the 727 route I assume I can just swap in my stock dipstick.

 

So, I bought the 727 for little $, figuring I have options now. But I'm still wrestling with keeping the A500 or going with the 727. Can anyone running an A500 on a 400 to 450HP setup, comment on the requirements to rebuild. If I just get the A500 performance build a kit from here:

http://www.makcotransmissionparts.co...R-K-BOX-1.html

Is that sufficient, overkill or too little? Time I add in a converter, I'll be sitting at $900

I could do the 727 rebuild for likely $300 less total (although I'd need a new drive shaft), but not have OD or lockup. Not a concern at the strip, but running 3000 rpms at 60 MPH for the occasional cruise to the beach isn't fun.

 

I would just use the A500. As far as beefing it up I would do the same modifications to it as a 904 an then whatever needs to be done the overdrive. The reason why I would use the A500 is not only because of weight but, that A500 has a lower gearset than the 727. So, the A500 has a 1st and 2nd gear ratios of 2.74 and 1.74 IIRC where the 727 has a 2.45 and 1.45 gear ratios. On take off and passing the lower ratios will help. Additionally, another reason I would run the A500 is because of the OD. If you plan on running anything like 4:10s or 4:56s in the rear it will help if you plan on driving at least 55 mph.

The only downfall is the A500 is weaker is because it is smaller transmission slightly and the planetary gears are a little smaller than the 727. I will say I've had better luck with 727s but, I had a bad rebuilder. There is a mopar rebuilder I will not recommend and I will send that to you in a PM. Just my two cents and also you'll either need a different flexplate. I think the A500 is neutral balance on the 3.9? right. I know a 318 runs a neutral balance. The flexplate B&M is easier to get for a 727 as B&M discontinued the one needed for a 904 application which should be the same as an A500.

 

Yes, the 3.9/5.2 are neutral balance, the 360 is externally balanced and I have the flexplate for that. The flex plate bolt pattern for the 518 is the same as for the 500, correct?

I'd prefer to try and do the rebuild myself. I have lots of time, am in no hurry, and am fairly mechanically inclined and can follow directions. There's just not alot out there on exactly what needs to be upgraded on the 500 for 400 to 450HP. maybe I should start googling 904's, as I believe they are commonly used on strip vehicles. The kits I've been looking at include the kolene steels and red clutches...I'd go with a billet servo. And all the other normal stuff, plus a trans-go shift kit. But do I need to go with solid bands? Or change the planetarys? I'm just trying to get a feel for how far to go with the upgraded parts.

 

Robert, why didn't you consider getting a 518? That would have given you the basic 727 with OD and lock up and they are beefier than the 500. Also we've driven down the road revving at 3000 plus and don't like that all, that was when we started putting in the overdrives and it brought the revs down to just around 2000.

 

Because the 518's in that era were non-lockup and had issues with fluid boil at OD speeds without a large trans cooler. I'm already limited with front end room because of the flat nose 90 and the 360. I could go with a all-in-one Becool but that's another $700. The later 518s with lockups as I understand it were RE's or electronically controlled, and I may go sans PCM.