Sorry this isn't about rx7's but I have a question. I was changing my valve cover gasket on my daily driver and was tightening one of the bolts to the valve cover and it broke off. It's the rear left one. Is it bad if I drive without it? Will it still leak? Or will the other bolts keep it from leaking? Thanks.

 

It should work just fine; if it leaks, then replace the bolt.

Actually, if I were you, I'd take the valve cover off and remove the broken bolt so you can replace it anyways. Typically, it involves a pair of channel-locks or vice-grips. Worst-case scenario requires a small drill-bit and an "EZ-out" bolt extractor. All these tools are readily available at any automotive store.