new build 65 c10 lwb 5.3/4l60 swap help needed

[kha4079]

whats up guys im building a 1965 c10 that originally came with a 250 c.i and a 3 speed manual transmission and im in need of some help. i bought the trans dapt 4595 engine motor mount kit from jegs but it looks like i need the rubber mounts that bolt on the frame itself. i looked online and everyone says use the stock ones but i dont think the 250 engine mounts will work. anyone know which ones to use with the kit? also can i use fbody long tube headers? its a budget build and i dont want to get doug thorleys since ive had nothing but bad luck with them in the past builds ive done. also since im doing a 4l60e swap (i have the crossmember, shifter and cable from a donor 65) will i have to shorten the stock driveshaft? or can i change out the yoke?? thanks in advance guys ill post pics up shortly