Posted by Daryl in Oz [210.50.228.4] on Saturday, October 30, 2010 at 20:31:28 :
In Reply to: question on 230 -251 interchange posted by junkyardog [72.224.236.56] on Saturday, October 30, 2010 at 17:57:45 :
There have been 25" engines in Chrysler products since around 1929, although they are a different casting to the later ones. The Canadian made Dodge & Fargo trucks from '39 through '47 all used the 25" engine. The mounting holes on the back of the 23" & 25" blocks from these years are the same, so you can fit up the rear end of either block size the same way. You may need to swap the flywheel to match up as there are some different diameters. If you change from a 25" to a 23" you need to make up the 2" at the front end. Leave radiator where it is, extend hoses, fit a fan shroud, or move everything back 2". You will probably need to fab a front mount unless you take the mounting plate off the 25". There are several variations in the 25" engines, but most of the ancillaries will interchange.