[toolboxchev]

I have seen a 454 with a distributor put in wrong then adjusted by moving the cap around until it ran. Did the same thing except it came out the exhaust blowing both mufflers off it.

Scared the @#$! out of the technician.

Small block distributors can shift off one tooth when installing them and still mate up the oil pump shaft. Throwing the timing out.

I think you have a timing/ignition problem also.