Easiest way to defeat ABS is to pull the fuse.

Try it this way to see if disabling it in 4hi will work for you. You may not like the braking characteristics. I tried it in the snow, and it was BAD. Almost slid into a ditch.

Yea you could find the wire and put a switch on it. Or the power wire coming in or out of the ABS fuse.

88 4R, 350 V8, R150 5 speed Sold <...uot; />
97 4R, stock, daily driver
98 Sienna, kid and dog hauler, wife's ride