Overdrive in an Aspen

I know this subject has been beat to death here but I am going to bring it up again anyway (and because the search kicks my butt).

I have a '95 Dakota 2wd that has a 318. I hit a deer with it about 2 months ago and the insurance company totaled it (big surprise ).

I want to know if the o/d tranny from that will work in my Aspen without butchering my floor. The tranny looks fairly wide and I don't want to got thru the work of pulling both trannys just to see if it fits then pull it back out of the car to have it rebuilt.

Thanks in advance.

I would say no, it won't fit without major surgery. The Aspen uses the same case design as an A-body. You may have the NV3500, which has an integral bellhousing and is twice the size of an 833.

I was afraid of that.
The tunnel is about the same size as an a-body, I think it is a bit wider but not to much.
It is an automatic not a manual, otherwise I would just use the o/d 833 that I have already.
I should have been more clear in my original post I guess.

Is your Dakota have a 500 or 518 transmission? Both are overdrives. The 500 is smaller, based on the 904. I'm guessing it would be easier, but that is a guess.

Someone on this forum has one of these overdrives in a 5th avenue, which is a very similar chassis to your car. Anyway I'd like to know also, so count this as a bump if nothing else.

both markmullins and I put A500's into our 5th ave's. the floorpans are essentially identical to a volare. if you cut out the center section of the crossmember that goes over the tranny, the A500/518 fit without actually cutting the floorpan. I made a big beefy bolt in x-member with 2 bolts per side to replace the cut out section, and also reinforced thecenter of the tunnel with some 1/8" thick steel topside. no structural problems so far, with about 7000 miles on the car since the swap.

Ok, it is sounding better all the time.
I don't know if the tranny in the Dakota is either one, I want to say it is a 42RH or something. The 500 pan looks like a 904 and a 518 pan looks like a 727, correct?

One other question I have is this...can I get one of those trannys to live behind 600hp?

500 = 42RH = 904+overdrive. 518 = 727+overdrive.

You want to talk to Mark Mullins on dippy.org - he's put a 518 in his Diplomat which should be close to an aspen.

518 is also known as a 46RH. Mark's on this board as well. when I get some time I'll repost my pics of my 5th ave swap.

ok, here's some pics and description of my install. pics aren't the best. first off, here's the chunk of the crossmember I cut out.

and my first go around with the tranny test fit. fits pretty good. the tranny mount is an energy suspension piece for a camaro. a little work with a rat-tail file and it fit perfectly.

the tight spots: there's a boss on the pass side of the tranny I trimmed for clearance

and a plugged fluid port is tight on the drivers side. either beat the tunnel with a sufficiently large hammer, or cut the tunnel and form a cover to go over it and weld it in (what I did, basically bumped this little section out ~ 1/2-3/4"

a shot of the crossemember I fabbed up from 2x3" square tube and some 1/4" plate stock ideally, for stiffness, I should have made the "ears" about 4" longer to spread the distance between the two bolts on each side. this crossmember is basically taking the place of the section I cut out. if I get some spare time in the next few years I might do that.

here's the 2 normally open pressure switched I'm using to control lockup and OD, tapping pressure off the pass side governor port, using these directions

in my 5th ave, the old rear amp switch is my cancel switch. I sourced the pressure switches from a local tranny shop (they're used in turbo 350's) for $7 each, and the vaccuum switch, I got from rock auto (application is an early 80's caprice or mid 80's chevy van).

line running from the governor port

vacuum switch, Standard Motor Products part number VX2. pigtail I got from a junkyard.

last but not least, here's the interior shot. I formed some 1/4" steel and welded it to the floorpan and body crossmember for a little extra support, and the chunk I popped out to clear the port on the tranny. this is after I welded, gooped it up with some seam sealer, and sprayed it with some duplicolor. you don't even feel either of these parts under the padding and carpet of my 5th ave.

a couple extra shots- here's the tranny cooler lines, all 3/8"...I used these couplers to make it easier to remove, as space at the tranny is tight.

another shot of the crossmember, and driveshaft I had shortened. the 42/46RH uses the same output splines as a 727, and since I had a 7290 yoke on my 8.75" third member, I found a used 7290 driveshaft for $60, and got the shaft shortened and balanced for another $50.

not specifically OD related, here's a shot of my custom offset isoblocks I designed and made (machined out of 30% glass filled nylon) that move the iso clamp plates relative to the springs giving the proper 44" perch to perch width for a B body rear in an F/M/J. added bonus? with a mill (or belt sander) you can trim these at an angle to dial in your pinion angle (IIRC I had to mill mine 2 degrees to get everything perfect, these have the ability to be milled giving you up to +/-6 in pinion angle change). brakes are a wilwood drum-in hat vented rear disc setup.

and the car it's all in, after body work.

Really awesome work Patrick that is one sharp ride. I really appreciate the advice. I'm going to try it myself with the SMFI motor and see how it goes.

Thanks,
Chris
Austin, Tx