my starters giving me signs its going out on my 92 Camaro RS and my mechanic looked up the parts for me but for some reason or another the 305 tbi starter is a little more than the 350 starter. i was wondering if it wouldn't hurt to just use a 350 starter, has anybody done this before?

*my mechanic says to the best of his knowledge it wouldn't make a difference

 

There are only a few things (in lieu of starter) that seriously matters;
1. Number of Flywheel Teeth
2. Bolt Pattern (inline or staggered)
3. Torque

Since you're trying to use a 350 starter for a 305, there is only a couple things to check.
If it is OEM, make sure you are getting one for the correct number of teeth (if you don't know how many teeth your flywheel/flexplate has, count them (use a piece of chalk to keep track)) If it's aftermarket, still check but a lot of them work with both 158 & 161 tooth.
Double check your bolt pattern, you should have both inline and staggered holes machined into the block, but due to crud and debris getting in the holes, I would stick with what you have.
You don't have to worry about torque unless you boost the compression ratio of the motor. A higher C.R. would require a beefier high-torque starter.

But to answer your question completely; you shouldn't have any issues putting a 350 starter onto a 305 and IIRC they're both inline bolt patterned too.