Here's a "don't buy cheap E36 M3" with the right end-result: I did not install the parts.
I inspected these flywheel bolts upon receipt and did not install them because they were JUNK. I could easily see someone installing these.. if you don't know how bolts should look you might not realize these are crap.
I received ATP "OEM replacement" bolts, part no. ZX-200. These are supposed to replace the flywheel bolts for a Chevy 60* V6 engine, original part number 476576.
They were so bad I ordered another set just to be sure they weren't knock-offs. I was even more surprised to find that they were very different, but STILL crap!
From left to right, the 2nd batch of ATP ZX-200 bolts I received, the 1st batch, and the original GM parts they are supposed to be "equivalent to"... LOL
The other side of the two ZX-200 bolts. I would not install even the one that says "good" because I don't trust this brand at all at this point. The metal still looks like crap..
Ok so what's wrong with these? More like "where do I begin?"
The first set of ATP ZX-200 bolts (left in the closeup) has stepped transitions (NO radii on these parts AT ALL), and tool marks under the head. The numbers on the head are STAMPED in -- you can barely even see them in the top photo. They were obviously not made during the head forging step, assuming the head is forged at all. The original GM part has nice radii everywhere, no tool marks, and an obviously forged head with a foundry mark and the grade (11.9).
The second set of ZX-200 bolts had a radius from the thread root to the unthreaded shank, and a smooth transition from the hex part of the head to the under-head surface. There were still tooling marks on the hex sides, but at least the numbers were apparently forged into place on the head. The second set is also darker in color, indicating perhaps a different alloy or heat treatment.
Both ATP parts were made in China based on the packaging. There are no foundry marks on any of them.
I sent an e-mail to ATP regarding their parts. This was the reply:
ATP said:
The ZX-200 bolts are sourced from an overseas supplier. We rely on the
supplier's engineering expertise to provide us with parts that are
functionally equivalent to the OE parts. We have not experienced any
problems with the ZX-200s.
Don't risk your life with crappy parts.
For the record, I ended up installing ARP bolts because I could get them faster than the GM ones. ARP makes very, very nice stuff.