Harmonic Balancer

Have a 87 stang. 302 with 351 windsor heads. E-303 cam with 1.7 rockers. I have 2 questions. First are the 1.7 fine with the e-303 cam or are 1.6 beter and why. Second is, the car was a 5 speed I am turning into an auto. I am biulding a bad a.. trans for it. Can I use my harmonic balancer or do I have to get a new since I'm going to an auto, or does it matter. I'm almost done with motor. I need to know.

See this motor has been built before. Long story how I got the car. Its bored .060 over which I dont like. The car ran great before had a lot of electrical issues. I have torn the car apart and replaced all the wiring harnesses. not sure which 351w heads they are. Stupid question what is PTV clearance? So should I change to the 1.6 rockers. Nevermind about the stupid question. I had a brain fart. Piston to Valve Clearance