There is no difference in external dimensions between a 413 and a 440. If the guy who installed the 440 used all the 413 manifolds, oil pan, accessories, brackets, etc. then your swap back to a 413 will be a breeze. If, OTOH, the 440 was installed used all the manifolds, etc. from the 440 and it was a much later engine then you will have some heartburn. Why bother removing the 440 to put in a 413? The engines look identical from the outside. Is the 440 shot and you'd rather have a 413 under the hood? Is the 440 a late production, low compression engine? Pete in PA Date: Wed, 05 Oct 2005 18:27:09 -0600 From: Mark and Theresa Elliott <deadfishe@xxxxxxxxxxxxx> Subject: IML: 413 vs 440 in a 64 crown Reply-To: mailing-list@xxxxxxxxxxxxxxxx Hey all you mechanical experts, What would one need to do to change out the 413 in a 64 Crown to a 440? What things would need to change/be replaced etc. I am not asking this because I am contemplating doing it, on the contrary, I am thinking about undoing it. A previous owner did this to my car, and I am wondering what it would take to undo this and put a 413 back in. Would I need to replace all my accessories like the alternator, AC compressor, starter etc? How about the radiator? Would it just be a matter of pulling out the 440 and dropping in the 413, or would I need new motor mounts (I may need them anyway). How about the transmission, would anything need to be changed there? Thanks for your input, Mark Elliott 64 Crown 4 door (currently with a 440 under the hood) ----------------- 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