origin s13.5 fenders
 

this cant be right feels like it will break

That’s not right mine were not like that

Both of mine fit that good they sound like there going to crack if I push them down

Yea mine lined right up, it’s fiberglass I would not suggest forcing them in any direction get in contact with who you bought them from

see thats the issue with the conversion fenders which is why i ended up going with the metal oem, then just have my body guy mate the s13 and the s15 fender for a much better and cleaner fit.

i have some conversion conversion fenders sitting in my garage right now and i know that my buddy i got them from had to use a heat gun and kinda mold the fender.

heat them up good and bend the tabs back down

This ^^

Heat the lip up and bend it down until you're able to bolt the fender. The resin will soften up and be manipulable. If the gaps and the finish of the fender are crap, then I'd definitely get in contact with the supplier.