4l80e conversion in 1985 suburban. What parts do I need?

[NickTransmissions]

Installed the transmission and drove the first time today. Either this shift tune is bad, or something else is off. This thing feels like a dog now, shift points are too low and worst of all, this thing shudders like a mother when the converter locks up in 4th gear.

Perform a driving line pressure test. Short shifts and TC shudder is likely low LP across the board, which is probably C3-driven. If LP is low, contact the company that man'ed or sold the controller for tech support, if you havent already done so.

 

[txaggie]

Perform a driving line pressure test. Short shifts and TC shudder is likely low LP across the board, which is probably C3-driven. If LP is low, contact the company that man'ed or sold the controller for tech support, if you havent already done so.

Thanks Nick. It’s a Holley sniper trans controller and all the line pressure looks to be pretty similar.

Perform a driving line pressure test. Short shifts and TC shudder is likely low LP across the board, which is probably C3-driven. If LP is low, contact the company that man'ed or sold the controller for tech support, if you havent already done so.

What is “C3 driven?”

 

[NickTransmissions]

Thanks Nick. It’s a Holley sniper trans controller and all the line pressure looks to be pretty similar.

What is “C3 driven?”

C3= communication, command and control.

What exactly are your line pressures for all range positions at idle and at stall?