I want to go from 28" to 30" Local prop shop says they can go 2" either way. Any thoughts?

Do you have any reference on those guys? 2" is quite a bit and done wrong, it will ruin your prop. With that amount of pitch adjustment needed, you should contact Brett Anderson of Bblades or Greg Hittner of Cutting Edge Propellers. Normal rule of thumb is +/- 1". If more can be done, it will often depend on the prop model and the condition ect. Did they say 2" without seeing your prop?

My marina said the rule of thumb is 2" on stainless. 496 Mag HO's-7000lbs stepped hull-5000rpm w/28's

I would just buy a 30 and sell the 28, what you lose in shipping will be less than the cost of reworking the props and you will have a better product in the end. Or keep the 28 as a spare never hurts to have a backup.

Are you hitting the rev limiter ? the 30's may make it lazy pulling out, lab the 28's

If you can only pull 5000 out of it with the 28's I think I would just stay there. If you were spinning like 5600 than I would concider 30's.

Why would you change???? That is exactly where you want to be???????

+2 isn't the rev limiter set at 5150 on the 496's?? I'd think going up in pitch to a 30" would pull you down to around 4600-4700 a little on the low side I'd think

A 30" here would take some labbing to work well. 4900-5000 is, as mentioned the ticket for the 496HO.
On another note, remember your 28" B1's are about 27" true pitch, if you consider changing props in the future. Before any work is done, they should be measured to determine pitch. If anything, have them balanced and re-pitched so they are the same, but stay where you are. 2 inches up will most likely take you down to 4600-4700 rpms, possibley even lower, since stock props can vary in pitch.

thanks guy's. think i'll wait till fall and have the 28's labbed.