Gosh, it's been a long time since the old forum was alive (or was that the old, old forum, 2 times removed). At any rate, I can't find the post of which you speak. I have saved several of my old posts, like the long one that addresses how to properly change a tire, and the one I wrote on rebuilding the rear shock, but can't find one on gearing.
However, 14/53
! WOW. I have trouble keeping the front wheel down with 14/47, and tried 14/49 once and could not even ride. Front wheel kept jumping up. Over Memorial Day weekend, I raced a REALLY tight 2 day event (did I mention it was REALLY tight), and ran my 14/47 woods gearing. I had to drop the forks 1/2 inch because it was REALLY tight, just to be able to get around, between, over, under logs and trees. Even with the tightness of this event, I still didn't use the cultch enough to cause any fading, and never once had to turn the knob on the quick adjust lever system I use.
One problem area where a higher rear sprocket may have caused some problems was on a narrow loose side hill, with a 90+ degree turn at the top, between two trees with exposed roots. My first venture on the side hill, I tried in first gear, and lost the rear tire off the edge. All subsequent trips up the side hill were in second gear to avoid wheel spin on the edge, and at the top as I jumped over the roots. The point here is that I believe you can actually go too much on the rear sprocket and hurt your riding.
My 13 year old rode his KX125, and was running 2nd overall expert for almost the entire event, until he hit a tree and broke his brake tube just past the master cylinder on the handle bars, so one of the fastest riders at the event. He had to finish the last 15 miles with only a rear brake, so lost 4 positions. After the event, he wanted to ride the course a few more times (not sure why, as all I wanted was a nap and a sandwich after two days of racing), so I let him take my 500 since we did not have an extra front brake hose in the van. He rode for another 2 1/2 hours, and was amazed at how well the 500 worked in the tight stuff. He didn't like the extra weight (but then again, he only weighs 150 pounds), but liked the fact that he was faster than everyone up every hill. He also liked being able to just gas it in any gear and get to a wheelie. Seems the 14/47 was just fine for Ben as well.
Test several gearing options for your type of riding, using the front sprocket as the gauge (they are cheap, and amount to roughly 3 teeth on the rear sprocket for every one on the front. For instance, swap to a 15 tooth in the front, and it will be close to a swap to a 49 in the rear. You can then ask yourself it it was too much, not enough, or just right. If was a little too much, swap to a 15/50. If not enough, try a 14/48 or 14/47. By swapping the front sprocket first as a test, you will have spent only $15, and should be pretty close when you purchase your first rear sprocket. But remember, when you get down to the final testing, one tooth on the rear can be the difference between really close, and just right. Once you find the combination that fits your riding style and terrain, stay with it.
Good luck.
Rick