Can a 340/5 be bored to 440

[GreenFever]

I am working on rebuilding a 440/5 for my '75 600 and I found a set of standard pistons and rings but I am unsure if the jugs I got will clean up and still be standard size. So I was thinking of getting a easier to find 340/5 engine from the salvage yard and boring it out to 440 size. Would this work? I was also wondering if pistons are swappable between all the CCW piston port 440 engines?

[Matt]

No, there would not be enough cylinder lining left to use. You're talking about an 8mm difference. I don't think good used cylinders should be that hard to find.
I'm not sure if the pistons are all the same, but they could be.

[lwb140]

loose is fast !! the iron jugs have to be really really worn or have to have been damaged or rusty to not clean up at std . tasky has some pistons for sale for this motor . my 340/s motor had been layingh in peices under the eve of a minibarn and those jugs cleaned up w/ .007 clearance with new std. pistons hope this helps wade

[GreenFever]

Yeah taskys pistons are the ones I am getting. So it looks like the jugs will clean up at a standard bore then.

Next question, someone really chewed up the threads on the flywheel side of my crank and I am not sure if it can be fixed. So will an older KEC 440/340 engine crank work in a KEC 440-5? I ask this because there are no KEC 440-5 or 340-5 engines at the local salvage yard but plenty of the older KEC 340 400 and 440 engines.

[Matt]

A '72 crank will not work, as it has a smaller output shaft, but '73 and on should interchange.

[Cabindweller]

If you chase the threads with a Die you might be able to salvage it.