Diesel Bombers - 01 E350 auto to F350 4x 6spd

Hi, im in mid swap from 2wd auto to 6spd 4x4 in a van. Im using everything from a 99 F350, the question is on the speedo wiring/ sensors. Iirc the speedo on the van is on the trans but is on rear ring on the truck. Can I splice into the rear diffs signal? I don't like abs so if I have to lose that option I'm not heart broken. What other wiring changes will I have to make to make the diesel run happily without transmission inputs to PCM, or will I have to swap in the trucks pcm? Vans 2001 and trucks a 1999. Thanks