Originally Posted by DDHoleShotAgain

Excellent description of the procedure I've used hundreds of times at salvage yards laying on the dirt. I never missed one.
Although I never thought to use chalk. The inside of each tire will have some distinctive marking for a handy index. I would rotate the pinion until my chosen tire index aligns with anything else; use rock to scratch bottom of drive shaft. Then, check the other tire for a similar opportunity. I would rotate the pinion 1 full turn, then check that both tires remained aligned. Then rotate 2 more full turns, to note positions of each. The final twist then finished my measurement to verify the tag.

This particular expert is not so convinced the TC and TH350 have not conspired against you here. I'm just guessing, but I have to doubt those are both original. These must match or the symptom you described is the exact result expected. In late 79 the TH350C was born which hydraulically actuated a lockup TC. Later, later, LUTCs went electric. If these components are mismatched, it'll not fail but keep your tranny in sport mode forever. If it's been driven like this a few weeks, then I would doubt tranny failure, because it would already have fully failed. Whomever suggested sniff the stick was running down that path. That's surely quick and easy to check.

I never have much luck with diagnosis from afar so I'm not saying this is it. But the evidence you presented, eliminates rearend ratio.

The conventional TH350 had part codes of M33, M38 & M39. The TH350C had codes of MV4, MX2, MX3 & MX5.

If your tranny and TC part numbers are correct, there are several other issues which plague GM cars. For example, If the tranny quit 20 years ago, the owner or a shop may have sourced any ole TH350 maybe with a C suffix, maybe not. The TH350 was extremely popular. Buick even co-developed. While the casings are nearly identical, the internals vary according to vehicle weight and engine power. So, if your car has a tranny from a V6 engine, it may never measure conditions to
lockup. If you now have a TH350C tranny which is not connected to your brake and thermostat, it'll never lockup. The TH350Cs typically came with a higher stall TC, because it could lockup instead of compromising with increased coupling.

Now that I chattered in circles, I'm sure it makes less sense to everyone.

Originally Posted by QIK59

Thank YOU so much for validating what I said and yes You and I have both done this innumerable times on our backs in bone yards - so easy and so definite !
I hear you re chalk - having to use a stone or stick to scratch a rim or sidewall LOL
You get it because you have actually DONE IT

I wondered if he has a lock-up Turbo 350 and is possibly experiencing lock-up in 2nd gear as far as thinking it went into 3rd ?

Originally Posted by PsychoTek

So reading your thread got me curious about "Kandi's" rpms so I had to check it. At 45mph she is at 1700, 55mph 2000, 65mph 2400, and 75mph is 2750

Originally Posted by Radovette

To all who responded to Radovette—thanks for your input. I now have some more homework to do to narrow this down. I’ll report back on a new thread with my discovery if any. As many have said in the past, the collective wisdom here is a wonderful thing. Radovette

Originally Posted by qik59

and what ratio has kandi's rear end
i'm thinking 2.73 !