I recently installed a pair of Rush slip-ons woth no problems - which is rare for me. I expeccted to shoot them through the garage wall when I cranked 'er up. Anyway, just put them as far as they will go over the header pipe and really tighten down on those bolts. By the way, I used the same clamps that were on my stockers.

 

You said it's a WG so they have the same exhaust as a FatBob. You almost can't go wrong lining up the bolts. The top one goes on first and you slide it in until the bolt hole ines up with the bracet.it rests there until you slide the bottom one on,and again the bolt holes line up,you bolt the two slips together there. If you put the torco clamps at least a 16th" back from the beginning of the slip-on there should be no problem. If you have a leak after that there is the high temp. copper paste Ratbob mentioned, But since you have to remove the pipes to apply that check there are no irregularities on the pipes themselfs before runniong out to buy anything. MY 2 cents!