swapping 82 727 parts into a 78 727 transmission case

[fueliedart]

I have a 1978 American Clipper 727 big block trans that I would like to rebuild (440 with Summit Racing FI already installed). I have an 88 727 smallblock trans that I rebuilt many years ago that was the "backup" trans for my 83 Ram that I have since sold. I don't need the rebuilt SB trans any longer and I was thinking that I would tear it apart, save all the internals, tear the BB 727 apart, have the case cleaned ,buy new seals and put the SB parts into the BB case and save myself some clean-up time plus put the newer parts to use. The SB trans was given only the best hard parts at the time of rebuild, premium clutches, bands and a shift kit. Both trannys are non lock-up. I have a brand new gear vendors in the garage that would also be installed at the time of reasssembling the trans. Anything come to mind from anyone that might be a problem as far doing what I have planned? Will the later valve body work OK in the earlier case? Should I have the convertor rebuilt and hang with it or replace it with a new "RV" converter and if so, what? I know better than to replace a 5 pinion with a 4 pinion planet set if I run into that situation and stuff like that. I would assume that being a later trans that the 88 trans probably has had improvements made over the previous 10 years that could only made it better and I'm hoping that no major mods had been done as far as the cases are concerned that would make swapping from earlier to later that would make this an unrealistic project.

 

[Professor Fate]

Rebuild kits are so cheap, I don't know why you'd want to swap guts- tear down 2 transmissions and end up with one.
I'd just throw a good kit in it, add a shift kit and be all done for under 3 bills; then sell the small block trans and probably turn a profit on the whole deal.

 

[AJ/FormS]

After cleaning, you could probably do the swap in an afternoon for possibly Zero dollars.
I would probably only swap the clutches and bands etcetera, unless one has more or better anything.. and would install the better sprag.
If you end up swapping gears, make sure they are the same and swap everything together, keeping the output shaft and the planetaries together as a set.
AFAIK, the VB's should interchange, but save the 440 one, in case you don't like the way the kitted one shifts.
If the Clipper convertor is clean, I would just reuse it.

No disrespect but, before I would install a GVod, if it would fit easy, I would have chosen a Mopar 4-speed od, which puts the od unit, into the trans, and is a .69od compared to the GV at .78.. The .69 is worth about 10%more rpm-drop at 65mph than the .78. Looking at it from the otherside, you could run 10% more rear gear for the same cruize rpm.
IE; 4.56 x .78=3.55s whereas 5.13 x .69=3.54 ..
Those 5.13s would get you a lil more drive off the line and a lil more climbing/passing gear.
On a different note, you can use the GVod to make a short third, by selecting od after Second gear. Then into 3od, you get the same .69 rpm drop, it's just not as low as if would be, in the Mopar od-box.

I have one of those Gv's, with a Manual Trans, and in my case, using it as a splitter, I love it. It takes a lottachit on the upshifts, just never try to downshift into it. and especially make sure it's out of the loop/disengaged, when backing up. They have zero-tolerance for backing up in gear.

But I imagine, since you already have the GV, you must have thought it over pretty carefully.

 

[fueliedart]

Rebuild kits are so cheap, I don't know why you'd want to swap guts- tear down 2 transmissions and end up with one.
I'd just throw a good kit in it, add a shift kit and be all done for under 3 bills; then sell the small block trans and probably turn a profit on the whole deal.

I need to clear out the garage. Good winter project. Trying to sell parts is more hassle than it is worth especially an old trans. Tired of dealing with flakes. I've had people offer way less than I am asking and half the time they don't even show up.

 

[fueliedart]

After cleaning, you could probably do the swap in an afternoon for possibly Zero dollars.
I would probably only swap the clutches and bands etcetera, unless one has more or better anything.. and would install the better sprag.
If you end up swapping gears, make sure they are the same and swap everything together, keeping the output shaft and the planetaries together as a set.
AFAIK, the VB's should interchange, but save the 440 one, in case you don't like the way the kitted one shifts.
If the Clipper convertor is clean, I would just reuse it.

No disrespect but, before I would install a GVod, if it would fit easy, I would have chosen a Mopar 4-speed od, which puts the od unit, into the trans, and is a .69od compared to the GV at .78.. The .69 is worth about 10%more rpm-drop at 65mph than the .78. Looking at it from the otherside, you could run 10% more rear gear for the same cruize rpm.
IE; 4.56 x .78=3.55s whereas 5.13 x .69=3.54 ..
Those 5.13s would get you a lil more drive off the line and a lil more climbing/passing gear.
On a different note, you can use the GVod to make a short third, by selecting od after Second gear. Then into 3od, you get the same .69 rpm drop, it's just not as low as if would be, in the Mopar od-box.

I have one of those Gv's, with a Manual Trans, and in my case, using it as a splitter, I love it. It takes a lottachit on the upshifts, just never try to downshift into it. and especially make sure it's out of the loop/disengaged, when backing up. They have zero-tolerance for backing up in gear.

But I imagine, since you already have the GV, you must have thought it over pretty carefully.

I've had the GV in the garage for 25 years now and thought it would be good way to use it. I thought about using a 518 and putting an Ultra bell on it but then decided I should just use the GV. I'm running 4.10's in a Dana 70. I decided that if I don't like the GV I can always go with the 518 UB combo and try that. I'm probably going to only be running 65-70 MPH on the freeways and don't see me going over that very often. My goal is to start getting rid of stuff and using up parts that I bought new and never used so getting rid of the small block trans and using the GV all at the same time would be a good way of clearing space. I also have a P4876878AB Mopar Performance convertor new in the box that I'm possibly going to install which I believe has a bit more stall than the stock 440 convertor but I haven't really checked the specs on it yet.