laying 20's

ok, to me through my measuring, an 8" notch should lay 20's out on a mazdawg, even with the front up. but a guy at a shop told me that it won't. no matter how many times i measure, i still get that an 8" notch will lay it out. am i right?

when i had 20 on my x cab the bottom of the axel didnt go over the top part of the frame rails it also depends on what tire you are running also but i doint have a tape measur in front of me but im sure an 8" notch will be plenty

thanks man.... will get on it on the crew cab then