What kind of rpm are we looking at when you are hitting 45mph i think we should go back to square one fuel air and spark
I have to assume nothing is blocking air passages or exhaust (although) you might check broken or plugged cat or muffler?
You just replaced most of your ignition system but how do things like your plugs look do wires pulled from the inner sockets on the plugs
Did you remove your distributor at all what kind of timing are we looking at?
And you just rebuilt the carb diuble and tripple check your work no offense just trying to help you out
