I tried installing the Transgo full-manual shift kit in my 518. Couldn't get it to work right. So I had A&A build me a forward manual valve body with a couple of custom touches.

Works like a dream.

As to the 2-3 overlap. I have struggled with that on 727s and 518s for years. After trying a bunch of different things suggested by the experts, I have found only ONE sure-fire way to get the 2-3 overlap out.

Use the Dorman 3/8" expansion plugs (#555-115) in the clutch passage. Start with a .090" hole. There will likely be a 2-3 flair-up . Then open the hole up a couple thousandths at a time until the flair is gone. Numbered drill bits #43 to #38 are handy for this.

If you go too far and need to back up, just run a screw into the hole and pull it out with a claw hammer.

Now, it is a very fine line between a small flair at WOT and the light throttle bang of slight overlap. You may have to choose between the two as I have had instances where I couldn't get all the light throttle slap out without having a little WOT flair or vice versa.