I hope there is somebody out there that knows more than me. But I do know that The 331 heads are different than the 354 but will interchange. You have to use the 331 water pump and housing with the heads BUT there are aftermarket water pumps that can be use too.. The early 331 heads use 1.81 & 1.5 valves but the late 331 heads use the 1.94 and 1.75 valves. Rocker assembles are interchangeable and so are the push rods. If I was going to build a engine from interchangeable parts I would research them before I bought them. Gary Barker Hardy Graham Jr. wrote: > Are all the Head components interchangable between the 331 and the 354? The > PAW "Early Chrysler Hemi" catalog lists many parts for the 354 but not he > 331. Are valves, push rods, rocker arm assemblies, etc. interchangeable? I > have been told that the only significant differance is the bore size. > > Thanks, > > Hardy > > > 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 > > 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/