Because Camaros, parts and tools for these cars are rather rare here, and because I don't have a spare input shaft I had to align the flexplate - pressure plate on sight. It was a little difficult to slide the trans in from underneath the car but it worked. The trans meets the surface of the belhousing fine. Can I be certain now that the alignment was correct or is it possible that they're just a friction out of line which could cause problems like stress on the splines or so?
Thanks.

If it slipped in without significant resistance and the faces came together tight all round with the bolt holes lined up it's probably fine. If you need the bolts to pull it together it's most likely not in right.

Each time you use the clutch and disengage the pressure plate, it lines up.

If you got the trans. bolted up without issue, you're good.

Just depress the clutch pedal and release it. This will free up the disk and eliminate any binding. Then tighten the trans bolts to the bell housing.

RBob.

The trans slipped in quite good and I depressed the clutch a couple of times. Seems like all is all right. Thanks for the replies.