I've never tried nitrous either... The original motor came with cast pistons so that would have been a no-no... Although I did manage to crack a piston skirt anyway without any help!
Instead of rebuilding the original motor, I opted for a J302 motor from a 98 explorer.
For those who don't know, the J302 sported a cast iron version of the GT40 heads and upper and lower intake. I sold the intake for almost 1/2 the cost of the long block...

Now I have forged pistons, roller block and a 1 piece rear main seal.
I wasn't floored by the performance with the new motor though, I'm guessing a B303 cam would wake it up though. My original motor with ported heads and a lumpy ford Motorsport cam made noticeably more power.
Other than that, I have Koni adjustable struts, KYB shocks, FMS springs, late 80's sway bars, 8.8 diff with 355 gears, close ratio rack, stainless shortie headers with 2-1/2" exhaust, torkerII intake and Holley 600 cfm carb.
Also I put a 86gt interior and turbo coupe rims.
Parts I have but not installed yet are crown Victoria brakes and sub frame connectors... I've owned the car since I graduated from college in 86 and have resisted all pressures from various people to sell it... Recently I've been thinking a bit about it so I can have more space for bikes in the garage but unless I get an offer that blows me away, I'm sure it will stay where it is!
The 85 is my favorite fox though... That was the year ford got it right, other than the faux dual exhaust.