That's a pretty major problem, Bowtie. The very first thing I would do is check the codes. I wish EVERYONE would do this before even posting a question. It's such an easy thing to do and can tell you a lot.
Did you remember to put the SPOUT jumper back in after checking timing? Is your distributor loose, possibly? Tell us what you've done to the car so far.
I can't even believe you asked if it was okay to race or not.
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351W 89 Mustang GT Convertible