If you are going to build an engine, with all of the expense and work related to that avenue, and are trying to decide between a 413 and a 440, the main difference in cost will be pistons - most of the other stuff is common. You'll be doing the heads while in there, and getting the seats hardened while you're at it is a good idea. If you must replace 413 pistons (some people re-use under some circumstances), they are increasingly scarce and consequently a bit more costly. The 440 has a habit of burning up valve cover gaskets due to the closer proximity of such to the exhaust manifolds, or at least that's so with most of the tired, old 440's that I've had. An aluminum MOPAR PERFORMANCE valve cover is much more rigid and may go a long ways to curing that problem. That and cork gaskets with sealant goo instead of rubber ones.... I have driven both and prefer the 413. It feels better to me, but I can't give you numbers to explain why. Seat of the pants calibration is a personal thing. Your 1965 was special because it had so many unique things about it, including the grille, headlight covers, 1yr only transmission linkage (lever operating cables to shift), and other things. Is being practical and functional significantly more important than staying stock? Do you have a line on a 440 that's a deal and no 413's in sight? I've sold through a batch of 75 used 440's and 413's. The 440's sold like crazy for all of the "project cars" of the muscle variety. 440's are highly prized in the marketplace and I was getting $500 for a really slammed, but rebuildable core. Can't give the 413's away, and its a magnificent engine too. If you're buying a replacement engine, and get an instant discount for a 413, that pays for the pistons right there. 64 & 65 are the most similar. 60-63 are slightly different, says interchange manual. They'll interchange, but I'd skip finding out the differences if you can get a 64/65. I encourage you to make the extra effort to put the car right. Nobody else will know, so it doesn't really matter one way or the other at all, but what's original is original, and this is a historic car that will only get older, more unusual, and (hopefully) more desireable as time progresses. Keeping it stock means no explanations or concerns later, but it's really not a big deal. I wrote you off list regarding the 413 that you can have for free from the west coast. -Kenyon ----------------- http://www.imperialclub.com ----------------- This message was sent to you by the Imperial Mailing List. Please reply to mailing-list@xxxxxxxxxxxxxxxx and your response will be shared with everyone. Private messages (and attachments) for the Administrators should be sent to webmaster@xxxxxxxxxxxxxxxx To UN-SUBSCRIBE, go to http://imperialclub.com/unsubscribe.htm