New 4 Speed
 

My brother once owned a 1967 GTO. When he purchased it, it was equipped with a three speed manual transmission. He wanted to upgrade to a four speed, and he found one at a local auto supply store / speed shop. They had a Muncie M20 for sale, but it had previously been damaged and the case had been welded up. The parts guy assured him that it was ok. He purchased the trans and a new clutch and Hurst shifter and spent the weekend installing it. For his first test drive, he had my other brother follow him in his car in case anything went wrong. Around town everything seemed fine. He decided to get on the expressway to test it at higher speeds. He wound out the gears in first and second, then shifted into third. As soon as he dumped the clutch in third gear, the trans exploded! He watched in disbelief as his brand new Hurst shifter disappeared through the floor. He tried to grab it but was too late. My other brother, still following, saw a pile of shrapnel, a drive shaft, and a cloud of gear lube shoot out from under the car, most of which he was able to avoid.
The parts store had sold the trans “as is” and did not stand behind it. Chalk it up to experience.

That really Sucks, Buying a used trans is kinda like a crap shoot. Ya never know what you are gonna get.
But really sucks that the guy he bought it front would not stand behind it. Hope he did not cause major damage under the car.
have seen many Muncie's at swap meets, usually over priced as well. But buyer beware I guess because you know you won't see
that guy at swap meet anymore. I usually look for the ones that need work and do the work myself so I know they are
reasonably good. LOL. Sorry for your Brothers experience.