It's been a while since I posted so here's an update on my engine project. I sent my first block (c6me) to the machine shop. It has no cracks and has one cyl. That can only take a .040 overbore. I then bought a complete 68 pickup truck engine. I tore it down and everything looks good at standard bore. Not even a top ridge on the bores. Never been apart. The block has no extra ribs but has the X in the lifter valley. Also no casting numbers on the side. I'm going to freshen this short block for a spare. Today I picked up a bunch of fe parts. 2 sets of C8ME=H heads, 4 390 flywheels, 2 standard bore block pistons, rods and cranks. I got this as a package deal. The guy wouldn't just sell me what I wanted and that was a standard bore D4TE mirror 105 block with extra ribs. It has the oil plug on the side for a compressor oil line. The casting # has a T in the 3rd digit. The water passages for the upper side of the block go way beyond the bolt holes and have a different shape. I have not pulled a core plug yet and measured between the cylinders but I think I have a thick cylinder block
BTW, I played 150 bucks for everything.: ) I'll be selling most of it soon. I just don't need it. I'll be working on putting my car back on the street in the future.