Long story short: just took down the head off my '72 350F about a month ago to finally fix the weeping oil that many SOHCs of that era had. Ordered my gasket set from David Silver Spares. Fully expected I'd have to find some taller oil galley seals on my own; didn't expect that the gasket set would have compensated for the short OEM seals.
However, I was WRONG! Turns out the gasket set I ordered from DSS, the NE brand, has TALLER oil galley donut seals that will fix the problem. See the photos attached. There's a photo of the gasket set overall, a donut gasket, a picture of the OEM donut seal I removed from the engine next to the new taller one, a shot of how the new donut gasket DOES protrude up above the headgasket prior to assembly (therefore it will touch the head and compress, causing a seal), a photo of using Permatex #2 non-hardening around the oil donut seals (both on the head AND on top of the gasket once you put the gasket on the head), and a photo of the Permatex #2 on all four areas right before putting the head on.
I've had the bike together now for over a month and have a couple hundred miles on it. Still leak-free, completely clean of oil. One thing: do NOT go crazy with the Permatex #2...you only want a light coat of it. It will squish out some when you torque the head down and you don't want it squeezing out of the side of the engine (almost impossible to clean off) or to get into the oil galleys of the engine. Just a little...like in the photo. On the cylinder side, then put on the gasket, then a little more on top of the gasket to seal the head side.
Thanks to "Hondaman" for his help during my rebuild. Also, I'm not guaranteeing that a seal set for your bike (400, 550, 750, whatever) will have these newer, taller seals, but am guessing if NE Brand chose to make 'em taller on their 350 set, they may have done it across the board in their product line. Good luck!
