Please help ID'ing a flathead

[Mountain Mopar]

New here, looking for a builder flathead for my 49' Plymouth. Preferably a 230. I know the Chrysler and DeSoto blocks are longer, but how do I ID the shorter block flatheads without a tear down? I have found a couple, but unfortunately the owners are not sure of size or year.

I would be interested in a good or builder 230 in the Denver metro area if anybody has one.

[Young Ed]

A good place to start is the code above the generator mount. The other way is assuming the engines will still turn over there is a plug over #6 and you can measure the stroke that way.

[Mountain Mopar]

A good place to start is the code above the generator mount. The other way is assuming the engines will still turn over there is a plug over #6 and you can measure the stroke that way.

Where do I find the info to decipher the codes and the stroke on various displacements?

Thanks for the help!

[Plymouthy Adams]

Ed is referring to the prefix on the engine block as it is stamped per vehicle application..application will lend a hand to CI of the engine..

as for the larger engine compared to the shorter engine use the tape measure the head length and remember 23 for the smaller and 25 for the larger, this gives you physical size only as a PO in the past could easily have swapped innards to go to a larger displacement where again, per Ed's statement, pulling the guage hole in #6 cyclinder will allow you to check the stroke and know for certain prior to any teardown..

[Guest P15-D24]

it's toward the back of the engine.

[austinsailor]

Take the engine number from above the generator, then find it here:

http://www.t137.com/registry/help/otherengines/otherengines.php

[greg g]

You can also check the stroke in the field by pulling the pipe plug i the head above number 6 cylinder. Inserting a piece of wire about 10 inches long and rotating the engine will allow the wire to ride the piston through its stroke and you can measure the distance traveled fro btc to tdc. 4 3/8 small disp, 4 5/8 bigger disp at least in Dodge, Plymouth and Dodge truck short blocks from 1940 forward.

The 201 ad 218 shared the 4 3/8 the 230 all had the longer stroke which was the difference between the 218 and 230 displacements. The 201 had a smaller bore to go along with its 4 3/8 stroke.

So for your purposes you're lookig for the 4 5/8 set up.