Just curious as to the different length comparing a stock 700r4/241 to a th400/doubler combo? I am getting ready to install my 400/205 and the driveshafts I have, the front should work but I will need to get the back shortened. I have another 400/203 for when I do the doubler but the trans needs rebuilt and I want to put lower gears in it and when I put that all in I am hoping to just get the shafts I have modified to save on getting custom shafts made. I know the front will need lenghtened for the doubler and the rear shortened again. Will the rear shaft work for the time being untill I could get a rear cv shaft? Just tring to plan ahead for the doubler.