rebuilt stock even 273 hipo. (10 to 1 pic stons and matching cam and intake will scare you in how well it runs. They are one of the most impressive motors i have ever sen. Able to slay giand of half again thier size. Why. good design. Hi revs because of small cubes cyl heads have no trouble feeding the 273. (Sort of like having a set of Eddys on a 440.) Must be the 4 bbl build though with the right pistons, not the 2 bbl thingy. compression in the 440. if your headsare 906s and measure 99 ccs then 060 will give 82 cc. Stock desired spec is 80 and 79.5 in one year so 80 is good. however we all use felpro blue gaskets now and they are .020" thicker than the priginal so i remove that extra as well. NOW I KNOW!! some of you ot there are thinking and saying you cant remove over .080" from aylinder head safely . In this case you can. Why? becuase you are not making the heads thinner than its diesign specs. you are taking it to the spec it was orignally designed to be. 80 cc minimum. If you wanted to stop at 82 cc Plus the extra cut forthe thicker gasket that would be fine in a street motor and would give you a margin for cleanup should you have a problem later however these BB mopar heads are oncrdibly outside of spec being way thicker and moe volume than most (ie smalll block heads are usuallly not much of spec) right here there is huge perfomance awaiting you. The pressure you have in the cylinder before you light the fire determines absolutely what your power will be. L23255F TRW FEderal etc pistons will give just over 10 to 1 and the Hypereutechtic from KB for te same engine also work very well providing your engine uilder can rerad and gives the top ring the huge end gap Hypereutechtics require as per the instructions . Also clearnaces need to be generouds. . Not tight. Evn KB allows you to add 001 clearance for cevere or pefomance use. your need at least .001" clearance per inch of diameter. absolute bare minimum unless you are over 90 , female and never drive over 30 mph. period. Thats my story and im sticken to it! Don Author of Return to Deutschland (True Adventure) Old Reliable (Mopar) http://altonapublicschool.faithweb.com/ http://seniordragster.bravehost.com/index.html [Non-text portions of this message have been removed] ---- Please address private mail -- mail of interest to only one person -- directly to that person. I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic. Thanks! '62 to '65 Mopar Clubhouse Discussion Guidelines: http://www.1962to1965mopar.ornocar.org/mletiq.html.