I just rebuilt a 350 and put it into my 84 TA. However, I was really bummed (while racing a 2000 mustang) to find out that the car wouldn't go over 110-115 ( hard to be precise with 85mph speedo). The car wasn't cutting out or anything, it just wouldn't put out anything else. I know the engine will go over 4000 rpm and it runs great, so I'm fairly sure it isn't the engine holding me back. I've heard of a speed limiter in the ecm. Is this true? If so does anyone have any ideas how to get around this problem rather cheaply?

 

Theirs an article in the tech section that may help you out. It says to basically put an on/off toggle switch in line where the VSS wire goes into the ECM. That way you can turn it off and on(speed limiter).

Note: You will get an SES light when the VSS signal is borken from the ECM...but you can go faster. After done playing turn the switch back on and the code goes away.

Read the article and it should solve your problem w/ the limiter...it solved mine!