With the recent thread about how
the 48RE was a better design for high torque and long miles of towing
how many of those improved design changes could be used
to upgrade the capabilities and durability
of a 1995 46RH?

In particular
what Torque Converter substitution
and what Overdrive unit changes?

What shops around the country could implement those changes?

The 48RE was a diesel only trans. If you talking '95 diesel then it would be a 47RH. If the 95 is a gas motor than it is a 46RH. Diesel torque converters are all to themselves and can't be used in a V8 gas application. Things you can't use from the 48 are, the torque converter, valvebody, trans and O/D cases, the rear band assembly, the output shaft and possibly a few other pieces but you can get most of the guts in there.

The 47/48's had more frictions in the drums and o/d unit. I had a 48/47 front drum added to my 94 46rh to up the friction count and also added in the needed pieces on the o/d unit to increase the friction count there. Put a 3.8 kd lever in too. Got ahold of an aftermarket converter to go behind the 5.9 gas that was going to get a 4" crank. Added the 48 pan too with a spacer for the filter. Had already done a shift kit several years before. The 46's also had different planetaries depending on what engine was in front of it. My 5.9 had 5 I believe. May have been 4. The 5.2 had one less, 3.9 one less than the 5.2. V10 and diesel had 6.

If going behind a gas engine you really don’t need all the geartrain upgrades.

Make sure you have it built correctly, good clutch and band materials, call it good.

The 48RE was used in the diesel and V-10 SRT truck.

I never saw any SRT units go bad, they were overkill for that application.

For sustained highway use in OD, the overdrive unit takes the beating - and the best you can do for a gas unit built before 2000 is use ATF + 4.

ATF + 3 was an improvement over Dexron and such but 4 is light years ahead of all of them. We started using it around 2000 in the trucks And it solved s lot of issues.

I seen an article somewhere about this. The diameter of the drums are larger and won't fit in a 46. Some of the other parts you can use. You can build a bullet proof 46 if you got the $.
https://transmissioncenter.net/product-category/dodge/

They fit in mine.

All front and rear clutch drums are the same diameter - regardless if 727/46/47/48.
What you may have heard is the L/R drum differs in diameter between these units. That would be true.

The “barrel” - the main case is the same between these units in regards to diameter.

You are correct, the 48RE was also used behind the truck cast iron V10, but those torque converters can't be used behind a V8 either as well as the SRT 10 converters. They aren't very common so I didn't mention them.

Agreed