460 to a 490?!
 

Title says it....I'm looking at a truck that has a 460 under the hood but was rebuilt 37k ago and bored out to a 490....I've never heard of this, some someone shine some light on it for me? Trustworthy?

To make a "490", you would need a .140 overbore. Not likely. Most people put the prudent limit for a stock block at .060, some say .080. After that, sonic testing of the block is the prudent step before more overbore. Some people say they have done .125 or even .140 overbores, but those required a sleeve or two. This is discussed in these two threads, as well as many others.

https://www.ford-trucks.com/forums/9...-overbore.html

https://www.ford-trucks.com/forums/8...f-a-460-a.html

If it was rebuilt that way, IMO that would not be a good idea for a truck engine.

What is more likely is that it was rebuilt with a standard .030 or .060 overbore and the seller is just guessing at the displacement.

Does he have receipts from the rebuild showing the piston specs?

Maybe it was bored and stroked..... or you were being stroked.