Air gage plug

I would like to use a Sheffield air gage for checking the cylinder bores of the model engines that I build. I need to gage .758 bores x 3.13" long in cast iron while being honed. So far the best information I have found is in http://www.edmundsgages.com/metworldart05.htm, but I thought it worthwhile to ask if anyone has experience/suggestions for making gage heads. Recess jets, flush jets with drain channels, sizes, allowance from nominal etc??

The reason for the odd bore: I am making several of these engines and I thought it best to ream to size after boring, then honing for final finish. Unfortunately I discovered that the import reamer was bent and that produced an interesting shaped hole. I decided to save the cylinder by boring all of them to the "first over-size." Otherwise they would have been .750+.

Thanks
Carl

I know these guys http://www.2si.com use air gages for that sort of thing. I haven't been in touch with them in years so I dunno who works there now, but you might luck out and reach someone at 2 Stroke who would be willing to help. Maybe Joe Stonebreaker (president) and Tammie Morris (QC) are still with the company....