Nameless Imperial Person My first thought is what is wrong with the OEM intake manifold that 413's, 4 bbl 426w's and first issue 440's had ??? My second thought is will the 15 to 20 pound lighter manifold make a difference on a car the weighs as much as your Imperial ??? If you are looking for get away power and better MPG figures on your car please think of just adding a dual exhaust to the car and keeping the diam no larger than the diam of the inside of the exh manifolds. The "X" will give ya more power from idle to red line, than using an "H". Since this is an Imperial ask for the longest high flowing muffler set that will fit in the space. I also use resonators that are the same length as the 1970 Crashlier 300. If this is not a big enough gain, think of this before you visit a non-national shop ( http://www.1aauto.com/1A/ExhaustManifolds/Dodge/PickupFullSize/PLP1390041/67559 ). This is a bolt in HP manifold that fits your car without using a hammer or special tools. No matter with vehicle hop up magazine that you may read, they all say to enhance the exhaust before you spend big un-needed bucks on the engine. Uncle Rodger & Aunt Gabby Colo Spgs ----------------- 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