Also, Pantera exhaust can be pretty restrictive. Not sure if you ran your stock (or stock-ish) headers/tailpipes.
My builder thought there would be ~50 more horsepower in my engine if I went to a less restrictive exhaust….
I run Hall headers, modified collectors and enlarged pipes to the stock mufflers…
I didn’t want to shell out the $ and effort for a new “bundle of snakes” exhaust system…
Rocky