moog with the 555 stamp are the OEM
Not sure what you mean here? Moog or 555 are definitely NOT OEM parts, maybe you mean OEM-replacement parts? Sorry just trying to clarify.
I'll pitch my 0.02 here:
I replaced my LBJ's early last summer as a preventative maintenance measure. If you search there are quite a few LBJ failures which cause the ball joint stud to shear right off or the ball joint bolts (4x) sheer off and sent the vehicle plummeting into the pavement. It seems to usually fail at lower speeds and "appears" to be more frequent on lifted vehicles. They say these should always be replaced every 120K miles regardless of how good or bad the condition of them seems to be.
Anyways, back on topic, I initially cheaped out and bought the "555" brand parts after hearing they were made in Japan and doing some research. I liked the idea of the grease zerk and chose the "555" over the MOOG brand part. I replaced both at once as well as the outer and inner TRE's, got an alignment, and continued wheeling and exploring. About 2 months later, I found I was getting some play in the front end. Checked all front end components despite them being "new" 2 months prior. Sure enough, both ball joints were having issues. One side the rubber boot had un-seated itself and had been allowing debris into the joint for who knows how long. The other side just had play in the joint. I removed both to get them replaced under warranty. After getting two new replacements, I opened the box and moved the ball joint stud around. It was like they were binding and not free to articulate, straight out of the box. At that point I turned around, got my money back, went to toyotapartsales.com and ordered OEM units. Lesson learned - still trouble free after a year and a half of hard use and I don't expect to replace the OEM units for another 120K miles. Do it once, do it right and get the OEM ones. After seeing the quality of the 555 units, I really would not trust their components on such an integral piece of our front suspension, especially one prone to failure on lifted applications.