My 90, as well as every other pre-97 ive done cps's on have been a PITA so much so that ive dropped the trans cross member for clearance before. When i did the one on my 98, i swear the bellypan is differant, because i had plenty of room once i removed the driveshaft.
The 3' extension works great on the early models.
As usual, online experiences very with model years and previous mechanical experience.