Originally Posted by heavychevydude
Hi guys. This is my first post on here so plase go easy on my. I have a '51 chevy stepside that I have had for years and I started a v-8 conversion years ago but was stalled until just recently. The motor I got was a 305 small block or so I was told. I needed to order some parts for the motor so I wanted to find out what year it was. I looked up the casting numbers and found out it was a 68-73 era 307. I was pretty surprised to find that out but I want to know if having the 307 is better or worse than the 305. SHould it make pretty good power for my '51? I plan on it being a daily driver but I want it to have some get up and go too. The engine has an "RV cam", block hugger headers, a holley quadrajet carburetor and a KN air filter. Is this a pretty decent set up? Thanks for any of your advice.
The 307 is just fine vis-a vis a 305, its a 283 with a 327 crank. Yes some blocks can be bored to 4 inches making a 327 with 327 pistons. You need to sonic check the bores if you ever go this route, early 307s, like 283s, will bore to 4 inches, later ones with thin wall casting techniques are so-so.
A 305 uses a 350 stroke on a unique small bore, it cannot be made into a 350 with a boring bar; so the 307 brings some innate potential for enlargement with factory parts.