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

[txaggie]

Howdy all!

We are building a 4l80e for the suburban and I have a sniper harness and controller coming for it to lip into our sniper II on the 461.

I have two issues. I need to keep the mechanical Speedo. What does everyone use for this? I see Dakota Digital makes one but I’m not sure how the sniper system will convert with it.

Secondly, does anyone use a special linkage for the trans shifting?

 

[Tonimus]

To keep the mechanical speedo, you need a driver. I just installed one of these on a '72. https://www.moderndriveline.com/sho...-speedo-converter-with-58-screw-on-connector/

The linkage on the 4L80 is further back than the TH350/TH400. For the '72 we just had to move everything back. Had to narrow one factory bracket and lengthen a linkage. LMC sells a semi universal linkage that should be super easy to modify or it may work out of the box. https://www.lmctruck.com/mechanical/drivetrain/csb-1973-86-transmission-shift-linkage-kit