305 Block Casting #
 

Looking at putting a 305 chevy together I have many different Blocks. I was wondering what was the best Casting # to use to build a 305 with. Just looking for some input.

thanks

Re: 305 Block Casting #
 

I have been told (can't promise it's true) that the 776, 777, & 778 (last 3 casting numbers) blocks are thicker than others due to them being a Canadian block???? Like I said, don't take this as a proven fact, just what I was told when we built ours. We have also ran the 909 block with no problems, but it wasn't on Knoxville's list so we changed.

Re: 305 Block Casting #
 

I got one other Question, what are guys doing on the mains are they leaving them as a 2 bolt or having them machined for splaed 4 bolt. Just trying to get a block ready to put together.

thanks

Re: 305 Block Casting #
 

Depends on what kind of motor you are building. We do splayed caps just for a little more strength.