welcome to the forum,
when you've changed the engine to the 16v engine, did you also change the gearbox, suspension and brakes to those of the 33?
or is that all still sud?
if you did change all that for 33 stuff, are your koni's 33-items, or sud-items, 33 ones are shorter
when i bought my '82 sud Ti, it was lowered with a cheap rubbish set of springs, frontsprings were ok, but the rearsprings were way too soft, even the original cloverleafwheels(14" from a series 1 33 ) rubbed like hell
and the car always was lower at the rear than at the front
so i took the rearsprings out, and compared them with other springs i had lying around
the sud loweringspring could be compressed very easy by using just 2 fingers
they were actually longer than standard 33 16v springs, but those 33 springs were much stiffer
so despite being an inch shorter, it raised the rear end of the car by almost an inch, so the car sat level again
handling was transformed, i've even put my fondmetals 5 spoke on the car to check for rubbing, they are 7Jx15 ET24, didn't rub on normal roads