Starter not engaging

Okay so back to the problem child... 71 SSP new 72 340 with original 904. Making a vibration noise that I was 95% sure was the flex plate rubbing that I posted about earlier. Just spent 7 hours changing the stock flexplate (which was rubbing) to a new B and M flexplate. Got her all back together and now the starter won't engage the gear. Starter works fine as I bench tested it. I did notice that the new flexplate moved the torque converter back some due to slight difference from stock one. So what now? Pull the tranny out and move ring gear or is there an aftermarket deeper starter you can buy?