I own an '89 LX with an older 302 swapped in it. The engine is carbureted. As I was driving home i put it in 5th gear and there was no acceleration, and the engine was revving at about 6k rpms. It is currently not drivable because of this issue. It has trouble starting now and when it does, it does the same high revving when in neutral just sitting there. I'm new to this forum and this is my first mustang and first engine with a carburetor. The engine is practically new and I know the tranny isnt messed up. I there isnt anything wrong with the throttle because ive checked when the engine is off the gas pedal still works the throttle isnt open. Whatever is wrong its causing the car to hardly be able to start then when it does it revs as high as it will go and it wont run. any ideas?