The below tips assume the body and frame are not tweaked from an accident
THE TIPS BELOW ARE IN APPROXIMATE ADJUSTMENT SEQUENCE - the way I did it and learned as I went along.
1) car weight must be on matching wheel sizes, inflated to spec, good springs, on level ground
2) 2 -7 body mounts must be good and torqued to spec
3) hinges must be good and doors need to be aligned as good as they can be, paying attention to the door striker gap, fit of the side contour(will never be perfect) the gap at bottom lip and the gaps at the hinges - if the doors are not correct everything else will be off
>length of doors must be close to equal - if not, compensate hinge locations(my doors had a 1/8" difference)
4) the lower rear fender attachment ears and fit onto lower bracket must be right - shim as needed
-the only fender contact points will be where the bolt positions are
5) the upper rear fender mount usually needs a shim or two
6) rad core bushings need to be good and torqued correctly - you may or not need 0 to 2 washers under mounts depending on fender alignment
- rad core can be adjusted left to right, forward or back, up or down to suit fenders
7) install fender liners last
8) the header panel(nose) determines the space between the fronts of both fenders
The factory publishes fit and gap specs - I feel it's best to trust your eyes for best looking final assembly
ps; I spent 12 hours to adjust everything from the doors forward for the most pleasing fit on my 86 ss.