Motor mounts, M-35 & M35 Cooling w/ Sherwood vs. Oberdorfer Pumps

[Breakin Away]

I fully accept that many (most) users can install an Oberdorfer N202M-908 in their M35B (or a self-customized version of a less expensive version N202M) and be happy with it. I do think that it is also important to note that there is a small possibility that a new heat exchanger may be needed to get it to work properly, as it was in Mick Laver's situation: https://c34.org/bbs/index.php/topic,8689.0.html

Going forward, it will be interesting to see if Mick's problem reappears once his new heat exchanger has fouled a bit, and if/when that happens, whether boiling it out will fully restore the HX's brand-new performance.

Do you have any statistics (from C34, C36, and other users) on the percentage of shaft failures with the Sherwood pump? How many of those failures had the sleeve upgrade that was supposed to solve the problem? I still have an open mind, and your answers to this may affect my future decisions if my Sherwood needs another rebuild.

[KWKloeber]

I haven't taken any meaningful poll but I know of 3. 
One on a 35B (likely no ring, but uncertain,) one on a 4-30, one on a 25 or XP (no ring called for on those.)
Certainly maintenance on two of those 3 was probably an issue. But that also goes to the point of "Murphy" - so therefore it's better to have an Ob in case pump maintenance isn't up to snuff.  Not an excuse, mind you, just common.  Zero known issues with cooling a 4 cylinder.
Looking at it another way, the fact one needs a ring and needs to inspect the pump each start up says something about the product that's the root cause of the issue.  Why Wb doesn't smarten up and have Sw make a bronze pump for them is beyond explanation. Sherwood makes other bronze pumps. If that did hen I'd wholeheartedly endorse using either one. The complicated parts is a downside but not a show stopper.

[Breakin Away]

Gee, I wonder why Sherwood doesn't smarten up and realize that bronze, not iron, pump bodies are the higher standard?????

They did.

https://www.catalinadirect.com/shop-by-boat/catalina-310/engine/engine-cooling/pumps/copy-of-water-pump-late-sherwood-12quot/

Now the debate can begin anew. 

[KWKloeber]

AND! It's only a grand.  Good deal.