Will 1970-71 RT-1 Stator plates interchange with DT-1 of the same year. are there any numbers on the 1970 RT-1 that identifies it as a 1970. I have several plates but the 1970 RT-1 flywheel ( with advance ) doesn't seem to fit. Thanks for any help.

On the 250/360/400 the stator plates will interchange from 1968 to 1979....

But as you are finding out, you need a "matched set" with the flywheel.  One other pitfall according to what I remember DEET saying is that some flywheels will interchange physically but the number of magnets is different so again you need a match. 

Sometime stator/flywheel numbers can be found in the Service Manuals.

You're right i tried a regular flywheel and they do match, can you run a regular flywheel on the 1970 RT-1 without the advance. Thanks again

RT1 stator plates position the points in a slightly different position , because of the advance mechanism
on the rotor . That was eliminated on the RT2 , so it's stator plate was the same as DT2 .
Technically you could install the non advancing stator / rotor , but if you didn't have the RT1 B barrell ,
with the compression release , kickback on starting might be a serious problem .

I might have a stator flywheel match I have several plates. Thanks for the infp.

If you get 360 or 400 you'll be going cdi but yes fits on the motor. & as been mentioned--advance flywheel & plate from a 'non' advance won't work although probably the flywheel will fit over the plate & then you'll wonder why the points won't reach the cam. Was a good system 'that' advance retard setup except just one more thing to wear out & rattle. My RT1 motor had that.
I'd better edit that--if you go "74 360 or later 400, or "79 250 you'll be going cdi.

Here's the advance flywheel just for refference. Can see how its sort of stepped back a bit on the face instead of flat.
photos.google.com/search/_tra_/photo/AF1...TJ37YRjuY3CeS8vjzAiS
& just because--here below is a regular one to compare the flat face. Although i've lightened that flywheel around the outside many years ago.
photos.google.com/search/_tra_/photo/AF1...eTSMb03pK-qemQcOZoOa
Sorry, try these links below as others i hear don't work.
photos.app.goo.gl/dYLRzna8tF1AVaVCA
photos.app.goo.gl/qU3VLARGm35L2zvy6
 

Thank you for the help