When I have done a pastrami with dry cure, which is normally my preference, I use a lot more cure than you did. I prefer a heavy coating, no meat visible. I do NOT add more cure, just more salt and spices. I follow the instructions, I use Morton's Tenderquik and it has not failed me. I do press the meat if it is more than 2 inches thick.
the meat thermometer was so far past the top reading, it read Taylor
"perhaps...but then again...maybe not..."