mancini frame connectors.....help please

i have a set of profile cut frame connectors for my challenger and was wondering if anyone has experience fitting them, the problem im having is they fit really well to the front floor but at the rear section there is a 1/4" clearance through till the rear subframe. my floors are original with no repairs or replaced sections. there is no evidence of crash damage, are the mancini connectors just a poor fit, they look identical to US Cartool connectors and the photo on Mancini's site is the same as 1 on the US Cartool site, urgent help needed as this is holding me up.
thanks dean

There's a ton of info on this subject in the archives. Search and you will find....

Everyone I have done needed a fair amount of trimming to make them fit snug to the floor. You can expect to spend about 2 hours a side to get a close fit.

seems that a 1/4" really isn't that much of a bother, at least they fit your floor contours, that's usually the main complaint, perhaps your car's original tolerances are just that much more?,....I'd just add a 1/4" thick plate to the caps end that needs to make contact with the ajoining member so it can be welded up,......eh!

thanks, i searched the previous threads and nothing was specific to the mancini connectors.

can anyone give me some measurements for the placement of the connector at the front?

Just line it up with the orig frame on the other side of the crossmember. If you are using a wire feed just split the difference on both sides an dleave an 1/8th inch gap on each side - easy to fill. Then go in with a good hot stick weld (or wire)to get some good penetration!!!!!!