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

 

[vr1967]

If it’s 2wd, you can use this.

4L80E Mechanical Cable Drive Speedometer Conversion For Your Housing you send in | eBay

On 4L80E's there are two styles of output shafts. Both drive and driven gears matched to your axle ratio and tire size are included. This is not a kit. Your housing must match the one in the pictures.

www.ebay.com

 

[Broken85]

I know this isnt exactly what you were asking but (hoping this helps the next guy), if you ask ChatGPT for a parts list and an order of work to switch a 700R4 to a 4L80E, it will give you a parts list, and a list of mods you need to make for the project to work. I am not naïve enough to think this would be a 100% solution for a project like this, but for the next guy who is trying to decide what a job like this will cost him and how much work it will take, this is a great tool.

 

[carnutjw]

I know this isnt exactly what you were asking but (hoping this helps the next guy), if you ask ChatGPT for a parts list and an order of work to switch a 700R4 to a 4L80E, it will give you a parts list, and a list of mods you need to make for the project to work. I am not naïve enough to think this would be a 100% solution for a project like this, but for the next guy who is trying to decide what a job like this will cost him and how much work it will take, this is a great tool.

Nope-not happening. I would trust any of you yayhoos before the terminator interweb tool. I would rather struggle through blindfolded. No offense.