Just as we answer your questions it would help if you would answer our questions.
Sorry. I intended to follow through with some answers / pics but most of my time on the site is done flopped back in a lounge chair with an old ipad that is not always friendly with the photo gallery up load process .... in fact that is my real-time location right now. I use the desktop computer when pics are needed.
Ron: Yes. I did get info on all the gauges but confirming my conclusions with you guys is always best before spending money ... ask me how I know
Also, my research is perhaps unorthodox. I find all the ‘Red Letter’ words on a thread topic where Wes gets tired of using the Socratic Method of education and just lists a summary of the needed info., like all the number variations one can expect on a M38 speedometer. I then go to the albums and cross reference the numbers with the pics. Finally, if there is any more needed data I go to the manual part numbers (knowing in this case there are different clusters that go with at least two different MC number ranges) ...... same with instructions on how to do stuff. Some may call this cheating, others may see brilliance in the method.
I took apart the main can (bezel/lens/face/needle/back screws) but did not mess with the guts.... may practice doing a cleaning job and experiment with replacing the face.
The speedometer I have is not on the M38 list. It is off a... I forget... let me check.... ah, there it is:
Wes. “For M38A1's after SN MD70114 the clusters ORD# 8376619 were provided by AC PN 1582890 and SW PN 502Z. Speedos used with these clusters were: ORD#7760396, AC# 1580260 & SW# 503A used with Cluster ORD# 7418835 (These were luminous units) up through MD70114 and Speedos ORD# 8376375 AC# 1582373, SW# 503C & AL# EO-12205 used with cluster ORD# 8376619 (after MD70114), 7954878 (Early M170) & 7954879 (Late M170) (these were non-luminous units). ”
Which explains why it does not glow in the dark and why I don’t need to buy a geiger counter and a hazmat suit. The thing is, I read all the threads I can find on a topic and if Wes is wrong about something then I sure will not be the guy that spots it. Maybe one of those other guys.
Time to look up threads on speedo vs drive ratio.
I know about the need to match gauges/senders and found the needed numbers. I will contact the vendors and press the issue... asking “does your sender (which is not off a M38) actually work with an original M38 gauge” ???
Gauges are a mine field with folks offering NOS/take off 'M38 gauges' for sale with numbers that don't look right. There is also the 'does it work' issue. Yeah. Lots of reasons to use repos.
Here are pics of the back side.
