Blown OEM602 - is it worth digging into it?!

[MercFan]

My buddy is having a new engine put into his '91 300D (602) - he's had some overheating issues he's been fighting and one day the engine started making high pitch noises like something was seized - we thought maybe the vacuum pump, but the noise persisted even when the serpentine belt was off...

We've learned from this forum that some of these engines have [edit] timing chain issues, but if the timing chain was busted I bet it'd sound a lot worse AND it probably would never start again... but this one does - it just sounds like it has a seized bearing (or something) - what do I know... The mechanic that's replacing the engine diagnosed it as a broken rod... I don't know any better but I'm having my doubts just based on the way it sounds - it's not a knocking sound, it's a screaming sound. Sounds like the oil in it was Rotella 5W-30 synthetic - probably not the best choice for the summer heat... thought I'm sure that would cause the catastrophic failure... .maybe?!

Anyway, the reason I'm writing this note is because I was thinking about buying it from my friend and tearing into it to do a little 'post-mortum' analysis on it just so I can learn something from it - and with a bit of luck fix it and bring it back to life again for a bit of money. I bet I can get it from him for around $200.

Is it even worth the effort?! What do y'all think?

James