727 - Converter Stall keeps to high, why?

I got a weird thing going on with a freshly rebuild 727 and a new 9.5" converter behinda 500CID with a roller camshaft making some nice horsepower! Street car, no race car.
First converter flashed at around 4000RPM although we expected it to be around 3000RPM. Otherwise the 727 shifted nice. (TF2 Kit, red racing clutches etc.)
The converter maker made a new converter and said it should get 800RPM lower flash stall.
The 727 was inspected after a few 1000miles and it looked brand new! All perfect!
Test drive a while ago with new converter showed 200RPM lower flash stall than before, although 800RPM were expected!
Converter builder really can't explain it and he said it's almost the tightest converter he can build in 9.5".

Now my question: anyone of you ever experienced somethign like that? Could it be a to low converter oil pressure? Something wrong in the converter lube circuit of the Valvebody? The line pressure can't be so bad since the clutches and bands looked like new when inspected and it was driven hard! But something really is weird here...

Any ideas?

You're worrying too much?
If everything is working well as far as driveability, I'd be happy that it is what it is. Just remember don't drive around in third gear low speed "up on the stall". People street drive 8" 5000 stall units.

2X

500 ci,roller cam and it's not a race car? If it were mine,I put that first convertor back in! No seriously,a 500ci motor will stall higher than a smaller motor.

the customer doesn't want it to stall this high... the cam starts to pull at 3000RPM, so 4000RPM higher is lost RPM.

No, it's not a race car... here tons of those 500CID cars drive around (illegaly since it's illegal to have more than 20% more HP than stock!) and none of them drives races (also illegal here or almost illegal at least)

But anyway, I am wondering what could change the stall besides the converter itself? If the converter pressure spring in the valvebody could do that for example?

I don't think it's a pressure thing , the stall is a function of the design of the internals of the convertor , convertor science is black magic. You might have to switch another convertor design .

what if the valvebody sends not enough oil to the converter like it happens in P? I would guess stall would also get higher / more slip?

By the way, it's an AUTOMATIC shift TF-2, no manual valve body...

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what if the valvebody sends not enough oil to the converter like it happens in P? I would guess stall would also get higher / more slip?

By the way, it's an AUTOMATIC shift TF-2, no manual valve body...

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If it has a TF 2 it should have came wit ha new manual valve to remedy that, it's not a pressure thing , it's the convertor , where did you get it from ?