Help my crap 60ft times!
Which SS springs? There's more than one pair for the A body. The 002 and 003 has always worked best for me. Are you using gas shocks on the rear? Those are not recommended. MP has the 2" longer hydraulic shocks required for the SS springs. You'll also cut your ET even more going to a 904 based transmission. Though, I would iron out what's going on now before making a change that big.