( _____ ) You will better off if you find a set of late 63/ '64 heads for the 361/ 383/ 413/ 426 wedge or first series 440 that have six bolts to hold on the leakie valve covers rather than the super leakie four bolt series that you have. Also the newer heads have better flow spec's than yours so the mpg and other stuff is better. The last set of heads that came on 400'sand 440's have the best of the flowing and cooling. They have a casting of 4006452 on them. If you feel the emails don't match from other Imperial people call 1-248-969-1690 and ask MoPar Performace the same question. Why purchase roller rocker's ??? If you want internal engine power have the heads ported ( # P 4120437 ). If you do this, the rollers will show their stuff. And it is an cheaper expense for the power gain. I wll save ya or any other 413/ 440 owner a ten buck bill if you port. Just email me direct. Your car weighs a bunch of pounds and trying to do as the 440 into the Dart gangs does not make a very happy Imperial driver. You must built and set your engine up for torque. Bottom end and mid range is your target, nuthin more. 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 '63 Le Baron w/std Air & some other good options '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