John- I’d say that if you are completely from the side that you need to scrap the ‘split’ and turn the 3 finger fastball that you’re working on into a change up (it basically is, but for me the circle change worked better). The split is designed to be pulled down from a more conventional arm angle. I threw from a 3 quarter angle, but sometimes I’d drop down to sidearm and that change would just dive from there.
As for a velocity to get noticed, it kind of depends on if you’re left or right handed. Everyone says the magic # is 90mph, but a lefty can get noticed at a lower speed. This is probably true for proball however, you can still go far pitching at 83-85, especially if your sidearm action gets you good sink. I pitched 4 years of college ball at 85-86 and topping out at 88, but never got a chance at proball. Sorry to be so long winded, good luck!!!