Yes it will.
Dextron
4L80
4l80e
2003 Chevy silverado door panel removal diagram
where dose the transwmission control solenoid go on 1993 chevrolet silverado truck
It will fit but it will not work. The 94 transmission is computer controlled and the 88 truck does not have the right computer or transmission wiring harness in it.
In need to get shifter off to remove transmission
If there is no drain plug you have to remove the pan.
Couple ways to go about it. Put the transfer case in neutral (or the transmission, if a manual), and you can tow it from either axle. If it has an electronic transfer case without a switch to go into neutral and an automatic transmission, you'd have to separate the driveshaft from the axle remaining on the ground.
No it does not have any vaccum lines.
The 2006 Chevrolet Colorado has a 5-speed manual.