Spool vs SG

my 657 case is out of a old truck and has 4.10's with a spool in it and a 7290 yoke for the strip. ($125 less spool off ebay)
But I run open 2.73's on the street for gas savings and to keep from getting tickets. It only takes about 1 hour for me to swap pigs, (I swap U-joints too). Running those gears on the street isn't any fun. But it saves parts and gas.