Re: 307 questions
I too had a 307. Proud to say was my first engine rebuild. Well, re-ring anyway. Had it cooked out. One piston had a cracked skirt, I prolly cracked it myself when I was taking it apart. So I bought one stock replacement piston. I did some grinding on the heads and intake. Not knowing anything, I was 15, I just did what I thought was a good amount of grinding. Then did a gasket match for heads to intake. Dad worked at a diesel shop with a valve grind machine, so on a Sunday, we went in and did a valve job on it. I had a pretty good quardajet off a circle track car, so it went on the cast iron intake manifold. I put a comp, I think 260 something cam in it, with new z28 valve springs. New rings and bearings of course, and away we went. Was a fun runner. I ran the hell outta that engine. Went into a 68 Chevelle I had. Would hang right with a couple stockish 5.0 mustangs around town. Revved the hell outta it cuz I didn't care if it popped..
Ended up in a buddys circle track car for a night, he was out of motors, was the final night. So in it went. I told him, put it on the rim around the track and keep er wound up best you can, cuz I'm sure it won't pull off the bottom like a 383 will. He did, make the A Main, think top 15 from it.
It was fun cuz I didn't know much, and was having a hell of a good time learning by doing. Knowing what I know now, I'd build something and overspend and take away any fun that could be had by being over critical in every aspect of the build.
Anyway. Build it. Sometimes we just need to build what we have to learn, have fun, save some dimes, and not get bent if it breaks. Good luck to you.