made my custom shift linkage....

That's some fine work.....but one tip. If you reverse the two forward gear levers, you will be able to run perfectly STRAIGHT shift rods to the levers. See how the cross over each other In the thira pic? If you reverse them, that will solve all that. What did you use for the shifter linkage, btw? Did you get a kit?

In reversing the 2 forward levers, do you mean by placing the 1-2 gear operating lever in the 3-4 levers place and vise-versa?

I made the linkage all from scratch. I got some stainless heim joints from Fastenal, some stainless tubing, and welded some SS nuts on the the ends of the tube where I used shoulder bolts that hooks it up to the operating levers. On the shifter side, I had my buddy machine 3 stainless steel fine thread bolts down to the inside diameter of the tubing, slid them in and welded them up...