is it what? possible for him to move his two top shift rails to his forward shift case? of course... if hes got them both, what do you think marlins kit is? in the front case... he will run ONE of his forward shift rails with the tab welded across it. OR he could find another topshift case and use it in the rear with his topshift crawl box. either way... you gotta have BOTH topshift rails for the rear case... and then either one top shift rail for the crawl box.. or one forward shift.... you will have less money into it if you stick with your forward shift... but less resale options. as a topshift can bolt on to EITHER TRANNY(or to another crawl box for triples) but a forward shift can ONLY be bolted to a FORWARD SHIFT.... also, there are different length forward shift rails... so it decreases your options even more. Im going to convert my own topshift if I can find the parts.... anyone have the 2wd/4wd shift rail that they pulled out of there crawl box that they want to sell cheap?