Step by Step 4L80e / 402BBC Swap

[mcmlxix]

I thought I would document my progress as I swap in a 4L80e and BBC into my 71 C/10 SWB Stepside....


I found a new in the crate 4L80e a few weeks ago.... GM p/n: 24211275
I can't seem to lacate this p/n on line. I think I'll call the local dealer tomorow and see what info they have... Supposed to be a HD version.


The 402 came with a TH400. The flex plate won't bolt up to the converter that came with the the 4L80e. Looking into my options...

The cooler lines vary depending on what year the transmission was designed and built. The newer ones have provisions for 3 coolant lines. They also have some snap ring type connection. Looks like the clips that hold our window crank handles on...


The newer ones have 7 bolt holes on the bell housing and the older ones have 6 holes.
I post more details as I get more details figured out.

There are a couple controllers available for the 4L80e and 4L60e. I am going wiht TCI because the price is almost half of thte Compushift one... Summit and Jegs sell them for about $650... But... You need to run a TPS. Throttle Position Sensor. They sell a remote moount version for $199.00. I bought a TPS off eBay for $20.00 and I'm going to attempt to make my own bracket...


My truck has a low hump cab. I have a removable high hump from the big block donor truck. I think there might be clearance issues but not sure yet. I am also replacing the cab bushings with new poly ones. The old ones are cracked and worn out... I want to be sure that a clearance issues isn't because of old worn out rubber bushings...