I have a 89 RS When I start it it vibrates and jerks.I just put a new distributer cap on and it started this.What should I do?Thanks

Check the firing order (make sure you did not mess it up).

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68SS ZZ4, 4sp T-10, 12 bolt, getting painted

78Z28, 330hp vortec, TH350, 10 bolt (just finished)