I have a 65 elcamino, stock drum brakes all around. I am converting the front to power disc and tubular upper/lower control arms, but the rear will remain stock drums. I am having some rally wheels made with custom backspacing for the rear so i can fit as much tire back there as possible. I figured after measuring all points of the wheel well that a 5 3/4 backspacing for a 15x8" wheel(9" overall width) would center the wheel in the well, but i forgot to consider the lower shock mount (like a dummy). My classic parts supplier Jim Dyer classic chevy in stockton ca said that he has 15x8's with a 5 inch back spacing used successfully, and mentioned the shock mount to me...(boy am i glad he did, cause i can still have the spacing changed as stockton wheel hasnt started on my wheels as of yet) BUT, has anyone used that much backspacing (5&3/4") on an A body with my set up in the rear and been successful? Should i just go with the 5 inch backspacing thats been tried and tested to work already and call it good? I need to call the wheel shop tomorrow if i want to get it changed before they start fabricating. HELP!