A stock 413 is 4.18 bore and a 426 is 4.25 bore. So how about punching it 70 over. Then you'd be right on spec for the stock 426 pistons. And the 10 thou cleanup over your current 60 might be just be just what it needs without much more risk. Like Charlie says, check the block out first. But you might have a very good plan. Keith Boonstra On 4/4/2011 11:56 AM, charlies@xxxxxxxxxxxx wrote: > > Antonello, > I would think that a .060 overbore is at the limit for this block. If > you need to go larger you might be asking for trouble. Eighty over > pistons may be hard to locate also. For sure I would have the block > sonic checked, then if it passes, have the block magnefluxed. If it > were me, I’d be looking for another block. Charlie in Ottawa > > On Apr 4, 2011, Antonello Jelitro <antonino.jelitro@xxxxxxxxxxxxx > <mailto:antonino.jelitro%40fastwebnet.it>> wrote: > > Hello > I have finally received the engine for my F, it's a 413 that has > already been overbored 0.60. There is some ridge at top of the > cylinder walls so would need an overbore. I would purchase pistons for > a standard bore 426, is this a safe thing? Has the 413 safely been > overbored to 426 specs? Any problems of overheating or oil > consumption? I would fit a set of heads from a 300 J with large valves. > ANy suggestion would be greatly appreciated. Thank you Antonello > > [Non-text portions of this message have been removed] > > [Non-text portions of this message have been removed] ------------------------------------ To send a message to this group, send an email to: Chrysler300@xxxxxxxxxxxxxxx To unsubscribe from this group, send an email to bob@xxxxxxxxxxxxx or go to http://autos.groups.yahoo.com/group/Chrysler300/join and select the "Leave Group" button For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm For archives go to http://www.forwardlook.net/300-archive/search.htm#querylangYahoo! 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: Chrysler300-digest@xxxxxxxxxxxxxxx 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/