1992 5.0L/AL9 engine throubleshooting

Hello Gents, we finished the transplant of the above engine into our 1972 Mach1, it starts beautifully with high rev for cold ignition, but after few minutes the car will rev up itself. any ideas why?

Some more background,

1992 entire engine/ECC/harnes/sensors etc came from the donor car.
added hooker long headers replacing the OEM, OEM H pipe + magnaflow 40's from the donor,

No change on the distributor or any other set-up, just pull and plance into the mach 1.

ideas?

I do not have tweecer or anything like that yet, there is not chip in the ECC and it was running Ok on the donor car.


thanks in advance
regards

Thanks jrichker, the challenge was that the power stering pump did not have enough oil, i guess the engine did not have any load or something, go figure...

this is a dead horse someone might say, but looks rather alive to me!!! music to my ears.

YouTube - Mi Mustio volando

not sure if i can post a link to youtube, i might go reaindin' lectured...

regards
and thanks for the inputs.