I cc the heads on all Mopar engines I build. Different customers want different ratios plus if you don't you won't get the best performance. As a rule of thumb. for every .020" that you remove either buy using different thickness gaskets or milling the head or block changes your compression about 0 .5 % so if you have 10:1 and you add .020" thicker gasket , you will have 9.5:1 compression. I try to take them to the tenth when custom building a engine. Just a Little info. Gary Barker From: <mwl1967@xxxxxxx> Sent: Monday, January 28, 2008 6:15 PM To: <mplindahl@xxxxxxxxxxxxx>; <richard@xxxxxxxxxxxx>; <chrysler300@xxxxxxxxxxxxxxx> Subject: Re: [Chrysler300] Replacing Heads & Gasket Sealer > > In a message dated 1/28/2008 1:02:18 PM US Mountain Standard Time, > mplindahl@xxxxxxxxxxxxx writes: > > FYI, I am using the newer style, open-chamber heads that I was told are > desirable for the gas these days. > The head surface was machined to guarantee flatness > > > Years ago when I built the 413 for my 300K I scoffed a pair of recently > rebuilt heads off of a 440 that was to be a race engine. The problem, I > later > found out was that the compression was lowered way too much in changing > from a > closed-chamber head with steel shim gaskets to an open chamber head with > composite gaskets. > > Although the car essentially runs fine, crossrams and all, it has never > had > the guts to really pull the car hard. ( just ask don Cole LOL ) Later > calculations indicated that the compression was dropped from around 9.5:1 > down to > around 8:1 with a corresponding loss of torque and HP. Several experts > have > told me I killed a minimum of 50hp. The bright side of the picture is that > the > car runs all day long on 87 octane garbage with nary a hint of detonation. > > When this 16 year old engine gets redone again I'll be going back to the > closed chamber heads. If you must use the open chamber heads you already > have > please consider using the oem style steel shim gaskets so as to mitigate > compression loss. > > Mike Laiserin > Phoenix, AZ > > > > **************Start the year off right. Easy ways to stay in shape. > http://body.aol.com/fitness/winter-exercise?NCID=aolcmp00300000002489 > > > [Non-text portions of this message have been removed] > > > > To send a message to this group, send an email to: > Chrysler300@xxxxxxxxxxxxxxx > > For list server instructions, go to > http://www.chrysler300club.com/yahoolist/inst.htm > > For archives go to http://www.forwardlook.net/300-archive/ > Yahoo! Groups Links > > > > To send a message to this group, send an email to: Chrysler300@xxxxxxxxxxxxxxx For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm For archives go to http://www.forwardlook.net/300-archive/ Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Chrysler300/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/Chrysler300/join (Yahoo! ID required) <*> To change settings via email: mailto:Chrysler300-digest@xxxxxxxxxxxxxxx mailto:Chrysler300-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: Chrysler300-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/