Which is why I asked which rear axle he has. The BBP 8.25 is narrower than an A body 8 3/4" with BBP axles. On a duster a 4" backspace with 15x8's and a BBP 8 3/4 would put you into the quarters with 255's.
Was there a reason for only running 4" of backspace on your barracuda? I know they have plenty of room out to the quarter, but those measurements should leave quite a bit of extra space on the spring side with 255's.
