My car is a 86 z28 that came with a 305 tpi. the first owner of the car wanted to get creative and did a trans and engine swap. he said he used a 87 Z28 motor which was a 350. he then bored it out to a 355. did the any of the 350's made in 87 come with a carb. cause that is the setup i have now. everytime i go for parts i tell them a 86 350 they say there isnt any. so i tell them 87 350 and they have it. any help would be awesome.

You are going to have to check the serial numbers on the back
of the block and on the heads

Nope, Gm made no carbed 350's in thirdgens. if you need a carb related part, tell them you have the 305 still. Otherwise get the part for the 350.

Except that the carb he now has (according to his sig) didn't come on any 3rd gen, either.

You're in the typical "no-man's land" of chain parts store support. The route to this habitation is any non-factory-like modification. The worst of all worlds is when you don't have a map from the person who took you there.

The way out is to know exactly what you have, from what model and year (or aftermarket source) it can be supported, and have a parts source that is willing to walk through the maze with you.