That's what I kind of figured. I now think I can see the gear through a hole bored into the pushrod galley, though.
http://remanufactured.com/images/67-77%20250%20longblock.jpg I'll pull the side cover tomorrow and, God willing, should be looking at aluminum helical gear teeth.
The 250 has no issues, runs beautifully, and is still very "tight" with good compression, and no built up sludge or mechanical noises. That's why I asked about the gear; I don't want to have a stupid fiber gear in it that may kill it. There's a thread right now below this one where a guy made a slightly higher than normal shift and sheared the teeth off a fiber gear in a 235, and that doesn't help ease my fear of the fiber gears. I know a lot of miles have undoubtedly been run with them, but they are certainly the weak link in a six that is otherwise seemingly unkillable, IMO.
As to the 230, the alternator and waterpump bearings are fine, it's not the input shaft bearing in the trans, and it's not the fan belt squealing; the timing gears are the only thing left I can think of that could howl like that. It's always done it, and I've never really cared much about it. The differential carrier in that truck spun a bearing at one point and tore up the ring and pinion, and at 50MPH that's howling so loudly it really drowns out anything else. It's a super high mileage truck/engine that's seen more than its fair share of use and abuse. Here's a picture of the engine under the valve cover:
http://s1067.photobucket.com/user/6...&_suid=13646931500540847220999615781 The picture after it in that album is the valve cover itself. It's well due for a rebuild.
Also, happy Easter everyone!
