Ok, so I finally tore into the differential on the 70 440 RT. With the engine nearing completion/break in/dyno at the engine shop, the 727 completely rebuilt and ready, original driveshaft restored, I figured the last part of the drivetrain needs to be ready and waiting as well. The 8-3/4 diff was the only part of the power train that wasn't original. Someone had dropped in a 741 3.91 SG and the original open 3.23 was long gone. $1553 later, and I have a new 3.23 and seal kit coming from Dr Diff. The only place I cheated was I went with SG. I figured if someone doesn't like it when I'm dead, they can pull the SG for originality and liquify one tire at a time.
Leading up to my question, disassembly was pleasant. Zero glitter in the lube and everything rotated super smoothly. All teeth look super smooth with no noticeable wear. I know the 741 is the least favored, but maybe someone would love it? What is something like this worth?
not sure of a $$ amount, but not much.
I have similar leftover 741 (but with a 2.76 gear), so interested in feedback you get.
Edit: my mistake, I thought the one you were thinking of selling was open. Certainly a sure-grip, and especially if it is the 3.91 gear with good/no wear it would be worth $400+ easy. Whether to keep it mostly depends on if you need that cash and what kind of driving you do. A 3.91 is pretty impractical on the highway unless you have some type of overdrive but if only street driving it is way fun. And if you race it might be worth having a spare but not likely needed if just cruising. Just some thouhgts.
Too bad I wasn't closer, I would buy it for my own car....I would say $400-$500 :alan2cents:
Well there used to be a rule of thumb...3:23's were $300, 3:55's $350, 3:91's $400, 4:10s $450 etc..That would be the same USD or CDN depending on what soil you were standing on...
Then the fact you have a good sure grip in there, I think it has to be worth that, you can't build on for that...YES shipping would cost a small fortune... :crying:
If I were in your position I'd hang onto it. Spare parts are always good to have around..... That and you might not be to enthused with 3.23 gears?
Let me know when you come up with a number. I've got an extra B-body housing and was thinking of going with a 3.91 if I went through the trouble of fitting it and the spring relocation kit. We drive between Milwaukee and St. Louis a couple times a year and swinging by Peoria would make for an easy pickup and no shipping.
Nothing wrong with a 741. Dr Diff actually thinks they are very under rated.
Having a spare diff in the garage can be handy to have. I have a spare 2.76 unit that went in the car while I learned about different diffs to buy and how to set up gears when my last set wore out.
I think you will like the 3.23's though. IMO, 391 is too much for a big block if you like to go for a cruise rather than doing stop light launches.