I have "blown" my 700R4 and was looking for another, when I came across an Allison that's currently in a 93 with a 6.5. My truck is an 84 with a 6.2. Questions are:
1: Will it bolt in?
2: What is involved with the swap, drive shaft, linkage, etc.
3: I've heard the Allison is better, what are the advantages?

Thanks,
Tom

Don't think it's an Allison. The Allison was introduced with the Duramax. That's probably a 4L80E. It's a stronger transmission, but requires electronic controls and a standalone computer for control.

Speaking of transmission controllers, did GM produce any vehicles that had a separate, standalone transmission controller, or did they all have it built into the ECM? Would be nice to know, might be possible to find a controller at a junkyard instead of the $900 to $1300+ for an aftermarket controller.

Don't think it's an Allison. The Allison was introduced with the Duramax. That's probably a 4L80E. It's a stronger transmission, but requires electronic controls and a standalone computer for control.
I haven't seen it, but that's what the man told me. Assuming it is, can antone answer my questions?
thanks again,
Tom

Seems to me it has been discussed before and the upshot of the discussion was that it could be made to work (assuming you could work out the controls), but it won't clear the cab floor. Still, rest pretty well assured it's not an Allison.

Some of the early 90's vans with the diesel/4L80E have a "standalone" control box for the trans. For some reason I recall it being under the driver's seat, but don't quote me on that as I'm not 100% sure.

Which Allison is bolted to the 6.5? I have seen and been told several times that the Allison 1000 will bolt to the 6.5. Assuming the 6.2 and the 6.5 have the same bolt pattern, (I think they do, but I do NOT KNOW) then an Allison 1000 will bolt to your 6.2. If it is an Allison AT545, I do not know but if it is bolted to a 6.5 it should bolt to your 6.2, IF the bolt patterns between the engines is the same.

Currently, I do not know of any Vendor making a controller for the Allison 1000. I have heard of several STOPPING development. On this forum or the Diesel Page, I have heard of an individual that was selling a controller for the Allison 1000. I think your best bet would be a non electric Allison AT-545 (they all may be non electric for all I know). Best info I have.

some of the trucks had them too. the controllers were hid in behind the glove box. you will also need the tps and tcc switch. I'm sure theres more than that but it's just things to think about

Speaking of transmission controllers, did GM produce any vehicles that had a separate, standalone transmission controller, or did they all have it built into the ECM? Would be nice to know, might be possible to find a controller at a junkyard instead of the $900 to $1300+ for an aftermarket controller.

The standalone controller you're looking for is from a '94 thru '96 G van or forward control van with a NA 6.5. That will get your 4L80E tranny working, UNLESS, it is a 4wd application, then it gets more complicated. The GM part number is 16196390. Was shopping them on car-part site today, saw several ranging in price from $50.00 to $125.00

some of the trucks had them too. the controllers were hid in behind the glove box. you will also need the tps and tcc switch. I'm sure theres more than that but it's just things to think about

From what I recall reading, the tps will not work with the 4L80E, you need the ESS(electronic speed sensor?)that plugs in on top of the oil pump drive in the NA 6.5. Could be a problem if you have a vacuum pump there.

the TPS is mounted of the passenger side of the IP. but that does remind me that you do need a different speedo( electronic not mechanical) I don't know what it uses for a engine rpm pickup if it has one. might want to check in the the tranny forum for that info.

the 4l80e was used before '93.I know they had them in '91 and possibly before in the R-series truck. I got stuck with PITA. I hate electronics

I have heard of an Allison 545 or something along those lines behind a 6.5l in the Step Vans. From what I have read on that trans though it is a non lock up converter, and was made for stop and go kind of applications, like school buses and delivery trucks. Can be used at highway speeds just not its main benefit. Also my understanding is that even the duramax uses the standard Chevrolet bell housing, same as our 6.2l and 6.5l bell housing, thats how it got mated to the 8.1l vortec also.