speedandsports.com list these pistons for a DT3. They have 23 standard pistons for which the part no. begins with "438" and 45 quantity for which the part no. begins with "308". What is the difference in the "438" and "308" pistons?  I thought a DT3 piston would start with "311".

Well that paste from their website didn't format correctly so I deleted that part. I guess the real question is just what is the difference in the "438" and "308" pistons.

438 pistons are for 74 DT 250 A
308 pistons are for 72/73 RT2/3 360 .

I think that the "311" pistons superseded to the "438". You can still find original "311" ones on fleabay.

I think I can get away with a first oversize, they seem pretty rare, there are second oversizes on fleabay, I just want a first oversize that fits, not concerned if it is a "311", just want one that fits.

Try contacting Enduronut on here for pistons and rings.  He is very knowledgeable and has a good supply with decent prices in my experience.

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Yep . . . I've got a few of the 1st oversize sets
Contact me for details if interested.
 

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