Overdrive or lock up surge??

[TWISTER]

I just bought this truck and it has a 700r4 and what is said to be a trans rebuild and it does have a new converter in it. What happens is on the highway it shifts firm but sometime it likes to surge or either between the OD or the converter trying to lock up. I thought I would ask what it could be before messing w the TV cable. Any thoughts. When I was underneath it the other day the transmission seems kinda hot and teh dipstick tube will always get pushed out if that helps? TIA

 

[350runner]

Get a vac gauge hooked to manifold so you can see at what vac inch it's doing at b4 you touch the tv cable.

Sent from the dust in front of you!

 

[TWISTER]

After some investigating work from what I gather the truck is a 2wd 305 87 and has had a set of 3/4 ton axles put under it w 35" tires. I assume the shift points are set via computer and w 4:10 gears and big tires and a weak motor it's hunting for OD and don't know what to do. This fix I assume is a chip program. But I have plans of a Vortec and carb on this truck. If I am completely wrong or right just let me know. Thanks

 

[350runner]

Take a look see by the brake booster for a lockup solenoid, then on the carb throttle linkage for the tv cable...

Sent from the dust in front of you!