Ok, I swapped out the rear end in my efi v8 conversion 66 to a 8" from a maverick. I was just given (0 cost) a "N" 9" 3rd member with 31 splines and a factory posi unit. I know I will have to change axles due to the splines, but will a 9" 3rd member fit into a 8" housing? I really like the width and have purchased the correct backspacing wheels to fit perfectly. I probably don't need the 9" but the posi would be nice. I also received a set of 351C 4v heads, that the gentlemen said would make a nice street boss. Any words of advice, seems to me the ports are huge for a street efi (I know it would take a boss intake) setup. Thanks in advance.