I'm in the same situation as you Bart, here's what i'm doing first:
full length weld in subframe connectors (received yesterday) keeps weak mustang body from twisting, improves handling and launch.
strut tower brace (kenny brown still en route), stiffens front chassis
8.8" rear axle upgrade (i have a 7.5") with 3.73 gears (eventually i'll get stronger axles and better posi unit)
upper and lower control arms (heard it makes a huge differance in handling and traction)
after that i may get drag suspension or new engine...depends on if i'm still driving it everyday. Good luck. hope these help.
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'84 Mustang 5.0 LX
My car