Where did you run the line to fill the bag? Do the springs go in big end to the top? Also, does the end of the coil face toward the drivers side on both springs?
you're doing the 5 lug convert right?. with 17x9's in the rear?...how much are you dropping the car....if you drop it to much your going to have to lip the outer fender to not have any rub especially if you go with a 275 or higher.
I believe that they are not supposed to drop the car, i have seen some pictures of mustang with them and they havent lowered the car, some people say they do a little. As for the pig tail, thats the part of the spring thats completely round, not half round right? Im not real knowledgeable on too much suspension stuff.
check the passenger side, rearmost corner of the gas tank (the flat corner peice, about bumper height.) my gastank had a hole in it already, so i used that for the line fill.
Mine were already installed by the prior owner, but the line runs through the top of the passenger-rear coil, next to the shock (a zip-tie holds it securely to the top half) and through a hole punched/drilled in the trunk area above the fuel tank - this is on a notch setup, hatchback might be a tad different. The gauge, itself, I have hanging by another pair of zip-ties from one of the tension rods for the trunklid. Not pretty, but it keeps it up out of the way.
Whomever ran the line previously didn't take the tailpipes into consideration (they were running dumps), and so the kid before me who had a pair of tails welded up wound up melting the air supply line in half. Had to re-route the whole thing again to the above config.
FWIW, the springs on mine appear to have lowered the back just a tad, maybe 1" in the rear, but the front looks like stock height ... kind of a goofy backwards rake. It does help with weight transfer (along with the battery being in the trunk), as the butt squats right down and plants when you take off. Haven't had a single problem with wheel-hop or lack of grip (aside from crappy tires) as of yet - my 60' times at the track this spring will be the true trial.
Not to hijack, but ... what're y'all running for PSI in the airbag on these springs, anyway? 15? 20?
read sig for times with Drag launch set. I cut a coil off of both fronts to lower car a little under stock height. Before I cut the coil the front was about an inch above stock height.
here are some pics of mine, sorry the car is really dirty.