('97 Blazer 4.3 LS 4x4 model)

So I have the typical 4x4 fail, everything visually works, except the truck. SO... switch time.
$15 tcase switch in hand and actuator bellows switch ordered...

Since the fail is usually TRANS FLUID RELATED, and that is from the failed tcase seal... idea. Add a drainable plug port to the upper FILLER plug (as a lazy temp solution)
See: https://www.ezoilchangevalve.com/sto...SABEgLccfD_BwE

So...
#1 WHAT SIZE IS THE UPPER PLUG
#2 has anyone already done this?

Yes I know this is not a forever solution and you SHOULD KEEP EYE ON TRANS FLUID LEVELS MORE OFTEN... but this seems like (after switch repair) this should keep (me/us) going...

Thoughts? And answers to #1 above please?....

 

damn...

https://www.ebay.com/.../FG7BNS-M22-1-5.../171668775897...

Ordered a new M22 1.5 plug, going to tap it and insert a radiator petcock!

 

1 1/8 or so if I remember right
Lets see juryrig and risk burning up transmission due to a lack of fluid { and yes it can push that much fluid in a few miles } or fix it right and not have the risk - no brainer to me .....