AJ are you using ported or manifold vacuum for vacuum advance? That makes total sense, I was envisioning a vacuum gauge in the car going up as the op went to full throttle.
Yeah I thought you mighta bin thinking that, which is why I jumped in to clarify.
I always run vacuum advance from the sparkport, on everything I have tuned. I only tune streeters, mostly sbms, and the largest cam I have seen was the 292/508 Mopar.