Muncie LISLE-W-P Drain/Fill Plugs Info M20 M21 M22

[XXXGoldL34M20]

I would like to do a story on my 1970 Chevelle Club about the proper Muncie Drain Plugs that came with M20 M21 or M22.
I can not find info on this subject on Google so I will ask the experts here if they know what the LISLE, W and P plugs was for.
Below is a photo of the different Muncie plugs.
Any info will be much appreciated also it would be good to know what plug belongs to what application.
Lets hear what everyone has to say.
I am guessing LISLE or P was for M22?

[Fast67VelleN2O]

All 1970-1974 Muncie transmissions (M20, M21, M22) came with the magnetic P or Lisle plugs since starting in 1970, all transmissions had the lower drain plug. I've seen both styles in these transmissions. It just depends on what they had on hand at that time. The W filler plug was not magnetic and came on the M20 and M21 transmissions that did not have a lower drain plug in 1963-1969 Muncie transmissions. I have also seen fill plugs with nothing on them at all for these transmissions (non magnetic). I have seen one or two different styles of Lisle Magnetic plugs for 1966-1969 Muncie transmissions. I do not have a picture handy at the moment.

[XXXGoldL34M20]

Thanks Matt
Great Info,
My 1970 M22 Matching numbers Muncie on my LS6 has the &quot;P&quot; fill plugs and someone told me they were incorrect so ............ they were wrong telling me they should be LISLE, lucky I did not change them [img]<<GRAEMLIN_URL>>/biggthumpup.gif[/img]

I have some original non stamped non magnetic plugs that I took off older muncies, good to know they were used as well.

[XXXGoldL34M20]

Matt
Is this the other design for the LISLE plug you referred too?
Or is this over the counter replacement?

[marxjunk]

i have a few 660 boxes, a few 010 and a couple 661s, and i just found a 72 M22 for my buddy, and its so nice it still has the paint marks ...even on the gears...it has nothing on the plug...same with my stuff..no markings

[Fast67VelleN2O]

Dan,

Yes those are the plugs I am talking about. Earlier Ford Toploader 4 speed drain plugs also received that style of plug.

[Kurt S]

There was a large discussion of these plugs in the past year - maybe on CRG?