Ok, now I understand the thought behind your post, and that you weren't just 'being Bob', like me and shadetree thought you were doing. So, now I can give the answer your looking for.
First though my main reason for the post was that wether parts are bought from them, Clevite, Interstate-McBee, the OEM, or who ever, the OEM part numbers (at least for the CAT parts) are all listed. If you've ever tried looking up every individual part for a machine on the computer at the dealership, or in an old parts book, it can be a royal pain. Heck by the time I got a parts list together for the D6 I'm working on it consisted 6 legal pages worth of gaskets, o-rings, etc for the first order. On top of those were the piston and liner kits, bearings, gasket kits, etc, etc that I also had to get when the machine shop guys said they couldn't get them from their source. In other words, simply having info like all the numbers for the different oversized bearings, etc all together like this, in one place, regardless of the company, can make things alot easier when it comes time to start ordering parts since they might be on several different pages in 'the book'.
Now as a real answer to your question, I have had some experience with their products but not to the extent of rebuilding a whole engine. Though I can't name all of their parts I've used over the years off the top of my head, I do know I've seen the name on parts boxes in various projects. Beyond that I've never had anything I've done come back with any sort of problems. I don't know how to explain it any other way, but typically when it comes to parts a lack of a negative experience equates to a positive experience...And the only way to have either a positive or negative experince is to give them a try.
Now as far as using only OEM parts, I agree, there are guys that swear by the OEM pieces and will use nothin else. Funny thing is that many OEM parts aren't actually made by the OEM who's name appears on the part. I've been in this business turning wrenches since I was old enough to start helping dad and have talked to alot of real parts men over the years at both dealerships and aftermarket outlets so none of this is any suprise to me. Things change way too much to even begin to say who makes what for whom, and often there are several places making the same part for one OEM in order to keep up with the demand. If that fact doesn't make sense to you at 'face value' then look at it this way and maybe it will. CAT, Komatsu, Deere, etc all build equipment and that's what they are good at. So when they need an engine they might design it but when the design is done they need someone who's job is knowing how to best make pistons, gaskets, etc at the best quality and for the cheapest price, to do that part of the work for them. The same holds true for turbos, transmissions, axels, gearing, hydraulic valving, etc. Years ago I'll give you the fact that alot more mfgs actually did more things/made more parts 'on their own' instead of farming it out. However as times changed, profits became more important, industries became more globalized, etc, etc the 'new' way of getting things done by farming them out to 'experts' has become more and more prevalant. Given the part may be made to a CAT spec, Komatsu spec, have an OEM part number printed on it, etc, etc, etc, but in the end it's still not "made" by that particular OEM, but by a third party....The same holds true for 'aftermarket part' parts as well. Heck look at Standard Motor Products that makes automotive parts. They make the same part for several different 'brand name' companies... All the same parts, several different brand names.... In the equipment look at JD and Hitachi, JD and Lieberrer, Shibaura and Ford, etc, etc, and the same holds true on down the line.
Sorry, got long winded there but maybe now you'll understand a little better why I say that you'll never really 'know' any company, regrdless of how long or how many times you've dealt with them...wether you think you do or not.
That's not to say that aftermarket parts don't come in different quality levels, they do, but even then OEM involvement means nothing. I say that because several years back I went through two CAT Classic (ie OEM endorsed aftermarket products) fuel transfer pumps myself and all leaked worse than the worn out one I pulled off. When I had to begin another project I turned things over to dad and he went through two more Classic pumps. Finally he wound up getting a rebuild kit for the forth one that included bearings that weren't so oversized that the seals couldn't make up for the shaft movement. On the other hand I've used CAT Classic parts for other things and they were just as good as the OEM, for half to one third the price.
In the end, especially nowdays, you never really 'Know Who' any company is even if you think you do, regardless of what they do or what they make. One positive experience is just that,and although you pray they are all positive, an equally negative one could very easily be just around the corner. Look back at the post I made the other day about the ordeal with an engine machine shop Dad and I have both 'known' and done business with for nearly 30 years as a prime example.
After me being me and explaining all of that, long answer short, you'll never really know anybody, or anything as the only real constant in this world is change.........
