Yes, there are for sure different dipsticks. Not sure how many, there are many though since they're intended for many different model cars, trucks, vans, RV's etc
There is a deep pan and a shallow pan, and the difference is very obvious. One is I'd say an inch deepl the other usually found on trucks is close to 3 inches deep. So if yours that you compared looked the same, then they are the same.
Awesome for you and the variable pitch Th400. I had a VP Th400 out of a 67 Olds that was behind an Olds 425. I wanted to use it too just for the cool factor of having 2 different stall speeds. I wanted to make a street/strip truck and use a toggle switch for close to stock stall, and hit the switch and go into about a 3000 stall. Well, as many awesome awesome projects and opportunities I've had with cool parts, that I had to sell to make ends meet, those parts got sold on eBay for about 5 times what I paid for them, not to mention all the other spare parts I had too. But yeah, get that done and let us know how it goes. I had trouble finding someone that build my converter the way I wanted it built and I knew it would be expensive if I did find someone, so that was part of the decision in selling the parts to someone who may have already had the converter they wanted.
What is sittting for an extended period? You know an older transmission that sits for several months or years will tend to harden the seals in the clutch drums and such and it won't move. After warming up a bit, you might get a little action out of it as the seals soften just a bit. If that's the case, I've had some real good luck in the past by adding a trans additive. I know I know, I too had additives to anything, engine, trans, anything, but I have to say, it's been more than once or twice where I've seen additives help an auto trans that sat for quite some time. The additives seem to soften the seals and make them a bit more supple and pliable to where the transmission will work again. I'll also add, if it does work out, don't have high expectation for a long lived transmission. But hopefully, it'll be patch job to get you by for a couple to a few months to when it's a better time to get a rebuild done. You can add 1 bottle and see what happens. If it's needs 1 more, go for it. If 2 bottles don't do it, then give it up, it's not going to work this time.
