So I have a 1986 Camaro sport coupe with the 2.8, I want to put a carbutated 350 in it, I know I need stiffer coil springs, but my mom told me that my frame is different(especially the 1986 ones) and it won't support the weight/power. Is that true?

Also do I need a new k member and sub frame connectors?

Your mom is wrong. 1982 frames do not have the holes for the proper transmission crossmember location for the 700R-4. '83 and later are all the same. K-member is the same on '82-'92...

No. To have built 3rd gens with different unit bodies (actually, 3rd gens don't have a separate frame) dependent on the engine option would have been problematic, assembly-line-wise.

Much more info on this commonly-performed swap can be found here: V6 to V8 Swap - READ BEFORE POSTING NEW! - Third Generation F-Body Message Boards

I don't think that's the real issue my friend. I think your Mom is gently trying to discourage you from pumping money into that car, and she might fear that the car will be ruined. Nothing against you, she's looking out for you.

It might turn into a bad decision. It might turn into a lifetime hobby (full of bad decisions ). I don't know, depends on your personality and your means (money). Playing with cars can be fun & frustrating, but I guarantee it will be expensive.

Wonder if it was her car first?

I agree