This above kit IS OEM, i would trust it.

A lot of aftermarket suppliers claim to be OEM suppliers and they may be, and they may have that generic saying in their parts listing for Mitsubishi parts BUT i will say on brand new Mitsubishi Motors made in Japan you see these above brands. You also see; ASCO (old Aisin), Akebono, Diamond, Denso, MHI, Diesel Kiki/Zexel, Mikuni and Asahi

One reason it's hard to find good aftermarket parts for Mitsubishi vehicles is that they actually make most of their own parts or own companies that make the parts. They typically don't build their cars with parts from the lowest bidder, and not because they're better than that but because they don't have to. Most other car companies buy parts or license tech from Mitsubishi, I have personally found Mitsu parts on Ford, GM, Chrysler (obviously), Subaru, Toyota and Nissan that were original equipment.

MMC is one of the few car companies that actually builds the majority of their cars so what you run into with aftermarket parts is that they can be way off in design or tolerances due to the proprietary nature of these fine machines. So while any old part might work on a FoMoCo or GMC (because that's what they're built with) it might only kind of work on a MMC.

Something to look at next time you're scoping out engines in various cars, note the blockyness and generic mating surfaces on most vehicles. Then look over your MItsu and notice how everything fits just a certain way and that things are formed to fit together, how even your Mitsu made parts are perfectly made to conform to their other manufacturer counterpart (radiator core support exactly conforms to your radiator side straps = MMC steel against Denso copper and brass).
It's in these details that tend to muck things up in the aftermarket world, so when the same Mitsu part will fit all 6g74s the aftermarket equivalent might only fit a few of the configurations.

So just remember that even though Mitsubishi Motors is a smaller car company than Ford, GM and Chrysler Mitsubishi itself is much larger than all of the "Big Three" combined. Look up Mitsubishi family of companies and anytime you find a manufacturer name on a part that came with your truck google it and it will likely take you back to the same place.

For extra credit look up some of the "sponsors" on the Mitsubishi Rally livery throughout the years and see who owned them during that era. Very interesting stuff <img src="/forums/images/graemlins/kewl.gif" alt="" />