hard 2-3 shift and ? slippage -IPMO

[388dart]

I have a 727 mrvb that under light load shifts with quit an impact on the 2-3 shift. I also have rpms at the stripe that are ±300 higher than last year.
The TC has been disassembled and checked - nothing wrong with it and my calculated slippage last year was in the 5.5% range.
This year with a complete new performance built 727 and the same TC the slippage calculates out to ±13%. we have even changed cases:angry3:
Anyone got any suggestions/corrections? miracles?
Can the tranny be slipping in 3rd gear? and how would I know? line pressure too low for this kind of build?
thanks

 

[340mopar]

Sounds like the sprag in the convertor is slipping.


Chuck

 

[388dart]

Sounds like the sprag in the convertor is slipping.


Chuck

The TC was taken apart by the company that made it and double checked and all was as intended, so they put it back together and I have since ran the car. Same rpms thru the 1/4 and same mph as before the TC was disassembled. The sprag may be slipping - short of changing out the TC I can't tell.