Todd As with any engine performace up-grade always do the exhaust system first. With you 1963 Imperial you can not run down and perchase a set of headers. The one thing that any one with a 1959 to 1966 Imperial or Le Baron is to use the exhaust manifolds that were on big block 1972-78 trucks and etc. The passenger manifold looks like : http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7981388355&category=33632&sspagename=WDVW . The drivers manifold looks like : http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=33632&item=7982694712&rd=1&ssPageName=WDVW . If you use these manifolds and the same diameter tubing into an "X" ( not "H" ) then into the mufflers you will have more HP and a very good flow. http://www.1962to1965mopar.ornocar.com/rodgergabby63.html Rodger & Gabby Colo Spgs '47 De Soto Custom w/Fluid Drive & passenger door mounted swamp cooler '62 Crown Coupe w/std A/C & Auto-Pilot '66 Le Baron w/dual A/C & reverbed AM/FM '70 Overlander - InterNational Dbl '77 D150 w/360, NP 4 Spd, 12 Bolt Axle, OEM Buckets & etc ----------------- 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