Would like OD behind my 440 in my RV.
What would work ?

I am assuming you are looking for an automatic OD for an RV and the short answer to that question is there is no OD that will bolt on to any BB Mopar.

The easiest thing I could think of for you to investigate would be to go the Gear Vendor OD route. Pricey unit but would probably require few mods to your RV...probably just a shortened driveshaft would be the worst. This is a unit that bolts on to your existing 727 (replaces tail shaft) and adds the overdrive. They seem to run in the ~3K range IIRC.

Skip the Gear Vendors and get a 518.

I'm putting one behind the 440 in my Imperial. Ultrabell has a bellhousing that joins the two. It requires cutting the bellhousing back to the front pump and bolting the new one up.

The transmissions are tough and not much longer than a regular 727. The OD ratio is .69 which is a bit better than the .79 of the GV unit. It's a few thousand dollars cheaper too.

Some people talk about the ability to split gears with a GV but I haven't found anybody who really uses it that way. It's a bit cumbersome to shift it like that.

Fitting the OD in a van body should not be much of a hassle.

I don't see why so many people are afraid of this swap. I don't see any challenges to it and I'll have under $1000 in the whole thing when it's done. That price includes the Ultra Bell, transmission, and rebuild.

my neighbor put a 518 in his motorhome and he loves it. it is behind a 360 though, which of course is easier

The answer is split 50/50.

It all depends.

The GearVendors has been used for several years in motorhomes and it may well be possible to buy an existing setup. I've seen the overdrive units at swap meets in the $1000 range, the company will sell you the rest of the parts to make it work. If you're savvy enough to get ths far, getting the driveshaft modified is a piece of cake. Many longer wheelbase vehicles have two-piece driveshafts and those are very easy to shorten.

The Mopar overdrive automatic transmission is also an atractive option, cut off the bellhousing and swap on an aftermarket one. There are issues with the sttarter, but can be solved, thousands have.

Building the 518 to handle 440 power is no problem either, as the front if it is a 727.
BUT, the later auto trannys have been strengthened for use in front of Cummins and V10 engines, and I'd think of looking at those. Electronic controls sound daunting but I believe are easier to get right in the long run. Having a lockup converter would be nice, as well.

In conclusion, both ideas are attractive and both if done properly will cost about the same. I'd start looking at swap meets or CL and start talking to your favorite modern Mopar auto tranny shops to see which way the dice will land for you.

Also, Feets, thanks for keeping your eye on the ball about cost. That's important. I hope your transmission lasts a long time.

R.

Who said anything about "built"?

Start out with a good junkyard A518 and do the swap. Remember, the car was moving when it ran into the immovable object!

R.

Now you've got me curious about the A518 swap. What is involved in cutting off the old bell housing for the ultra bell conversion? Where do you cut? Where do you drill? Is there a diagram for this anywhere?

I believe the replacement bell housing is held in by the bolts that hold in the front pump. The 'Ultra-Bell" kit comes with longer bolts to account for the thickness of the flange.

There is another way.PTC trans has a kit that uses an 95 or older A-518.The 361-440 block will have to have the drv side lower bolt area cut off the block to clear room for the starter.No ultra bell only an adapter.They also have a very slick way to run the overdrive and the lockup.No on-off switch to reset at every stoplight.

I think I'd like to avoid cutting an ear off the block.

A pic of the 518 with an Ultrabell housing installed.

Feets - this is off the subject - but have yo had any problems
with the turbo bearings? Do you use a pre-oiler or hydraulic accumulatorS?

Thanks!

I've had one turbo coke the bearings but I think it was due to a poor drain line angle. Engine torque smacked the line on the frame rail and angled it upwards. Oil was slow to drain and cooked in the bearing housing.