Hi guys,simple question but will likely bring many different opinions which is fine,i would like to hear them all before i make my decision which is:

I am having the original #'s matching M20 muncie from my car completely rebuilt/resored and in 69 the M20 didnt come with a drain plug and that's the question at hand.

The praticality in me say's yes to install a magnetic drainplug for ease of maint to enable me to change the trans oil yrly or at least every couple yrs .doing that could extend service life not that i put many miles on it but moisture & metal contam from wear are nice to be gotten rid of with a simple & inexspensive yrly or biyrly oil trans change. But then the other side is my car is a true #'s matching 69 ss 396 i bought off original owner 30yrs ago and i wouldl ike to know if it will hurt the resale value down the road with a non original drain plug installed in the original #'s matching 69 M20 that didnt have a drain plug installed from the factory,thats the question.

I am currently leaning towards having the builder install a magnetic drain plug (kinda 60% yes/40% no)but still havent fully decided.

Thanks....Scott

In most cases I always do the drain plug but, not for a numbers matching vehicle.

Thats a tuff one. You no how simple an oil change is with a drain plug. Anyone would love it if there was a drain plug there and it would be accepted, but the one person thats is numbers matching crazy to perfection will suffer.
Your choice, but if I where to end up with your car, I would love it with a drain plug. Just my opinion. There still means of draining by the suction devices available.

I just recently posted an excellent reason for doing this!!! But I can't find it, so I'll go over it again.
First, all Muncies, until 70 when they all got a magnetic drain plug, had a magnetic donut glued in the bottom of the case. The magnetic donut does a very good job of pulling metal to the bottom of the case--------------------BUT THERE IS NO WAY TO CLEAN/REMOVE THE METAL FROM THE DONUT unles you tear the tranny down!!!!
So, have the donut removed and install a magnetic drain plug.
Also, it is rare (you'll see below), BUT, if that donut ever comes unglued, BYE, BYE Muncie!!!! :(
Below is a side by side comparrison of a magnetic drain plug, a removed donut, AND, that blob is a donut that came unglued and destroyed a very good M20--------------even busted the case!
http://i65.photobucket.com/albums/h219/DZAUTO/Driveline/100_1406.jpg

EVERY gear (except 3rd) either had busted teeth or the teeth were severely pitted from metal particles circulating around inside the tranny. I have NEVER seen a front reverse idler gear with ALL of its teeth sheared off like the one in this Muncie. All that was salvaged was the 3rd gear, the main shaft, rear reverse idler gear and the sliding reverse gear.
http://i65.photobucket.com/albums/h219/DZAUTO/Driveline/100_1407.jpg

Now, that beats originality. Sure can't argue with Tom's evidence.

Got that point loud and clear too,the stock magnet donut will be removed from the trans case.

Thanks....Scott

I Like Toms Suttle Way Of Explaing Things
Tom For President In 08 Jeff

Pictures can paint a nasty story, great point made.

Excellent photos Tom.

Both of our Chevelles have their original Muncies. Now Tom will have me driving like a long tailed cat in a room full of rocking chairs. VERY nervous. Gotta blame someone. ;)

Understand this!
I AM NOT saying that the magnetic donut IS going to come unglued and destroy everyone's Muncie. But, how long ago was it glued in there? How long is that glue going to hold? And, if it does come loose, you can see the potential for damage throughout the tranny.
When the day comes to open up your Muncie, it is just tooooooooooooooooooooooooooooooo easy to pry out that donut and drill/tap that lower boss (the boss is in EVERY Muncie main case) for a drain plug. The threads are 1/2in pipe threads, the drill size is 11/16in. If you are only going to install one drain plug in one Muncie just one time in your life, you may not want to invest in the drill bit and tap. I've been building 4spds (mainly Muncies) for over 40yrs and started putting in drain plugs over 30yrs ago. So, the investment has paid off for me.
I used to buy the magnetic drain plugs from Chevy parts dept for about $6ea/5 at a time until they discontinued the plug. I searched the net and miraculously discovered the original supplier to GM!!!!! I bought 100 plugs @ $.5oea!!! :thumbsup: Got a "few" left.

Got that point loud and clear too,the stock magnet donut will be removed from the trans case.

Thanks....Scott

I removed my stock magnet donut from my M20 and glad i did, it was just about to come un-glued. I drilled and tapped my case myself at work than rebuilt and replaced what was needed, it's not hard at all.

If a darn oil drain plug is going to stop someone from buying your car someday, so what. There's always another buyer around the corner that won't care.

Tom/kieth/Jody/LEO,Guy's,thanks Again For All Your Experience And Opinions,i Appreciate It.

KIETH,just cuirous,do both of your original muncies have NO drain plug and the original gear oil in them from 39+ yrs ago or have you had the trany's out along the way for clutch changes and simply drained the oil out through the fill plug hole while trans were out of the car?

I am hearing stories from muncie builders that they have seen plenty of mucnies without drain plugs that they believe had the original factory gera oil in them 30-40 yrs later and the trany's the werent abused like at the drag strip regularly were stillin decent cond when they were disassemble to be refreshed,is that really the case with this situation?

My car will never see many miles yrly and i dont abuse it at all, i only twist her up through the gears once in a great while when car is already in motion . I do it that way as to not suddenly load the drivetrain with a hard a snap like from a dead stop when dropping the clutch and no power shifiting either. I always use the clutch these days when short shifiting it at approx 5,200-5,300 rpms max as to not hopefully not hurt the original #'s matching block which is plenty enough fun for me hearing the motor sing with the lrg q-jet secndaries fully open while twsiting her up a little through the gears once in a while,dont want to break my baby that i have owned for over 30 yrs which is why i dont abuse it,can't afford to break it .

Scott

Hi guys,simple question but will likely bring many different opinions which is fine,i would like to hear them all before i make my decision which is:

I am having the original #'s matching M20 muncie from my car completely rebuilt/resored and in 69 the M20 didnt come with a drain plug and that's the question at hand.

The praticality in me say's yes to install a magnetic drainplug for ease of maint to enable me to change the trans oil yrly or at least every couple yrs .doing that could extend service life not that i put many miles on it but moisture & metal contam from wear are nice to be gotten rid of with a simple & inexspensive yrly or biyrly oil trans change. But then the other side is my car is a true #'s matching 69 ss 396 i bought off original owner 30yrs ago and i wouldl ike to know if it will hurt the resale value down the road with a non original drain plug installed in the original #'s matching 69 M20 that didnt have a drain plug installed from the factory,thats the question.

I am currently leaning towards having the builder install a magnetic drain plug (kinda 60% yes/40% no)but still havent fully decided.

Thanks....Scott

I asked this before but never got an answer. Do they judge the cars sitting on the ground as they do corvettes???? I don't think a drain plug added can make a difference and if it does it will be small.

My point is unless someone slithers under the car in the field, how will they see it????

Scott, the M20 in our original car had to have a bearing replaced when the car was about a year old. That oil is still in the transmission. It will be changed out when we do bearings, synchros and seals before putting it back in the car. That had close to 200K miles on it and still worked fine. We had new synchros, bearings and seals put in the M21 in our L78 car about 10K miles ago. Slight bearing noise that I didn't like. I really don't know the history on this one other than it appears to be original to the car with about 150K miles. Neither trans has the drain plug. With the COPO car, I'll probably just remove the magnet and take my chances. Cars like it are probably best left appearing original for future value if nothing else. Our 396 car has a CE engine so I'm not quite so particular about what I do with it. I do have a spare M20 so we have options.

That last pic is cool looking. Kinda looks like art. Horrible carnage for the muncie though.

Kieth/Wally,guys,thanks again for the your insite/opinions/and experience.

Scott