What you have will be a 305 cid, they were also made in 351 and 478 as well. These are big, heavy engines, I seem to recall that they weigh in around the 900 pound mark. They are a very torquey engine, not fast, but very powerfull on the low end. There was also a v-8 and v-12 based on the same block, and deisel versions that used different heads and pistons. I've poked around on the site that chevhelper posted, it's very informative.
