Horrid story about a 67 Chevelle SS car. Nightmare

[67 GTO]

How could someone not notice? My GTO was loud, with a 428, manifolds, 2 1/2" pipes, and 2 chamber Flowmasters. When I forgot to fill the diff I didn't get more than 20 feet without noticing the noise.

I have to ask: was this a Turbo 400??

I'm asking because I had a similar lockup incident which I attribute to a TH400. The 12 bolt from this instance was good for another year of use and abuse (and only because I went from 4.11s to 3.55s) but this transmission was a neck breaking piece of crap. No offense intended, but my well intentioned friend who built it clearly didn't know what he was doing - three broken cases and two flipped sprags. Anyways, I'm just saying don't rule out the trans...