When I changed out the valve cover gaskets on my K10, I found that the heads were different. Right side is a 74-76 76cc 350/400, and the left side was a 80-86 60cc 305! I called the previous owner (a friend of mine for 10 years),I tell him about the heads being different, and asked which head he had swaped out. He told me he swaped out the left side ( hmmmm..., I thought). So the right side is for that engine. I get the block # of it and check it at Mortec, turns out that I have a 350 in the old beast, not a 305 like I'd thought!:D I love nice little surprises like this:D:D

If you pull one of the heads you can definately find out if its a 305 or a 350. The pistons in a 305 are about the same diameter of a beer can...... Trying to cross #'s can sometimes be tricky, since Chevy put out a ton a variances through the years.....:skull:

If it is a 350 with a 305 head on one side.You should swap it out for a 350 head the same as the other side.THe 305 heads usually have smaller valves and smaller combustion chamber.This will raise the compression to a level where you will get pinging.My buddy has a 350 we pulled cause it was running terrible and ready to go.We started looking at the heads and found the same thing.One 305 head and 350.Blazin

I do have a set of heads for it, I'm just waiting to get some other parts first before tearing into it. I figure I'll throw in a new cam/ lifters, and timing set in when I change out the heads. Should make for a fun Saturday:D The previous owner of this truck wasn't too swift when it comes to engines!:rasta: