Any transmission experts in the house

[durty harry]

After getting the motor swap and rear diff swap done I was getting excited about driving the 82 again but my excitement was cut short .
I installed a 383 shortblock using the same top end , vortec head intake , carb and cam as with the 355and i, swapped the old 10 bolt pegleg with 237s for 12 bolt and yukon posi and a set of 373 gear but the 700r dosnt like something , It shifts 123 before I reach 20 mph and the overdive is non existent , I notice when in let my foot off the gas it just coasts rpms go to idle and when I pull the shifter from overdrive to 3rd I can feel it shift down the rpms go up . \
Driving at 70 mph the engine is turning 3100rpms and I can pull the shifter from OD and nothing .
Yes the TV cable is adjusted correctly and still has 12 volts going to the lock-up
The trans wasnt touched during the swap , shifted fine days before I started the swap
The fluid isnt burnt, has less than 3000 miles on it since rebuild .
Im at a loss

[68c10owner]

I'm not a expert but changing from a 2.73 to a 3.73 will change the shift points. You may need to mess with the governor.

[MikeB]

Originally Posted by durty harry

I notice when in let my foot off the gas it just coasts rpms go to idle

Not sure about a 700R4, but in a TH350, the intermediate band is there to provide engine braking when you let off the gas (vs. freewheeling) .

As for the shift points, I found the comments below at HotRodders.com posted by a guy who at least sounds like he knows what he's talking about. If you google "700R4 shift points" you'll probably get 1000s of hits.

"Light throttle shifts (depending on what you would call light throttle) should be roughly 15-20 mph for the 1-2, 25-30 mph for the 2-3, and 35-45 mph for the 3-4 shift.

MPH for WOT shifts will vary depending on engine and rear end gearing, which at that point you will be looking for WOT shifts to happen at or near redline of the engine.

When it comes to governor calibration, the springs will affect light throttle shifts (the lighter the springs, the later the shifts), and the weights on the governor will control the WOT shifts. (less centrifugal weights will allow higher rpm shifts.)"

[rayfinseats]

Shut off the engine and hole the throttle to the floorhard for a few seconds. Did that fix it? Sometimes a valve will stick in a 700r4. If that isn' it I'd check the TV cable and then put ina new govner.

[turbosix]

I'm no expert either but I’m +1 it’s the governor. I look at the governor as a fail safe. It will shift the trans into the next gear regardless of gear selection to prevent blowing the motor. As the drive shaft speed increases the governor pressure increases and eventually overcomes the TV pressure to shift the tranny. With the lower gears, the governor thinks the motor is reving too much. Shortening the TV cable adjustment will help but I don't think it will fix it. Again, I'm no expert.

[durty harry]

Sounds good fellas , I will pop the cover off and see what happens