It is indeed! And all this done while I was sitting in the waiting room at my dentist!

We had ACL bearings over here years ago, very good but I believe they have become part of the Mahle group these days. They had some very good and relevant info too.

When I ran my 170 slant six in "stock eliminator" I had no lube problems. Later, when I started hoping up the slant, I stared having some rod bearing issues (in particular number 5). Started using full groove mains and that solved the problem. Initally used upper shells in the lower position, but be a cheap skate I hatted to buy two sets of bearings, so started making my own, buy using a cutoff wheel in a die grinder, and grooving a stock lower shell. Not very deep or wide, and done free hand (they look like crap), but seem to work. I have never had a bearing issue, since, doing this. In my opinion, this is the Key statement in that write up.

"This is the key point about the bearing groove design and indeed any bearing feature - the
optimum design is entirely specific to the engine type and regime it is operating under. It is
not correct to make a general assumption about the optimum groove design and apply it
across a range of engines and operating environments. What is suitable for one engine may
not be suitable for another. The engine analysed in this study had a main bearing that was
sensitive to the difference in groove extents of 180° to 270° but a rod bearing that was not.
This, of course could be entirely different for another apparently similar engine."

So I will keep doing what works for me. Your results may vary.
PS: I have used many different brands of bearings, and did not see any difference.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225