Why is my top speed 70 mph?

Sounds like he has a good handle on working on cars, so I'm leaning towards the electrical side of his posts! If his car has had a number of things replaced or maybe upgraded to electronic ignition, maybe there is not enough fire in the hole to run it! Something in the wiring, or maybe running the stock coil with electronic ignition may be limiting the output of the ignition system??

Just thinking out loud here, and I still think the throttle pressure linkage could be the problem! Something about his post of over revving before shifting into the next gear gives me the feeling that it is/has not been adjusted properly, or not hooked up at all, and is or has burned up the trans!!