i was browsing the pages and came across this website that has all engine sizes specifications. and i never new a 305 could be bored .060 over which becomes a 315 cubic inch and not just be bored .030 over to become a 310 cubic inch. i remember seeing something on TGO that you couldnt something about coming close to the walls. not sure. can anyone verify this for me? heres the link. check for your self http://www.chuckschevytruckpages.com/enginespecs.htmlthanks

 

Some blocks with no core shift can probably bored out .060 or perhaps even more. Some blocks with core shift probably can't.

Boring isn't done to increase displacement, it's done to clean up worn cylinder walls.

 

I'd have to get into my books but i believe .030 is the max you can SAFELY go on a 305 before you start getting near the jackets, its been awhile though

 

If you're planning on going above .030 you should have it sonic tested anyway.

 

Depends on the 305 block. I have 2 305 blocks in my garage that are VERY thick castings(Sonic checking says .450" in the thinnest spot, and the block is already .040" over). The virgin block is almost .500" in the thinnest spot. The .040" over 305 took forever to warm up with the thick walls. Both out of 3/4 ton trucks/vans. One is 4-bolt main. Maybe you can only go .030" over on F-body blocks, but .080" over pistons are available for the 305. Another ounce of proof, is most 350 blocks weigh right at 200 lbs bare. This bare 305 weighs 230 lbs.

 

Hey, that's cool I didn't even know 305s came in 4-bolt mains. I know it depends on where and when the engine was cast. A freind was telling me of when he worked at a GM plant (in Canada I believe) where they manufactured 305s. At some point the machines got off and either the oil gallies or the water jackets or something got cockeyed. Obviously they didn't stop them until they penetrated the cylinder walls. So plenty of engines had some thin walls before they corrected the problem. So I can see why some would be capable of much overbore and others not so much. This may be old news, I guess I don't know how common that knowledge is.

 

thanks for the info.