the point that it can block up oil galleries is fair to say, altho every honda and alot of manufacturers actually use and reccomend these sealants

cant rely on the filter to clean out any silicon before it gets lifted to head? or would the pressure push the silicon through the filter?

I'd be more concerned about it blocking bottom end oiling holes.

Just remember that the manufactures want to sell more cars and parts. Ford uses loctite in ford brand and normal style. What's the difference you may ask?, money.

As for myself I don't mind the silicone goos but I really try to avoid letting stuff squeeze out and giving it some decent drying time.

threebond, toyota or nissan, loctite master gasket is good too
dont trowel it on
permatex good on cork n paper(thats what it was made for) but most late models use no gasket at all
have used sikaflex in the past but it is so strong you will destroy the sump if you need to get it off
dazza

when all else fails use what the manufacturer used, thats why they pay their engineers to come up with this stuff. permatex no3 is good, but cant be used on sumps. first hand experience when one of my mates decide to do that on his 202 hq, good fun watching him clean up brand new oil from absolutley everywhere lol go with silicone stuff. but permatex ultra black didnt work for me. with the proper usage and directions there should be no need for it to block oil gallerys and passages, except where copious amounts are used, or the product hasnt fully cured before being used. resulting in it corroding away into the flowing oil.
but dont let us scare you mildman lol

I go with ultra blue or ultra copper silicons; just give it time to cure -24 hours minimun.

I highly recommend genuine Toyota sealant, its good stuff for coolant and oil. Its about $35 a tube. 3bond is also real good but pricey and a little harder to come buy.

Just rang Nissan Oakleigh - a tube of geniune Nissan liquid gasket is $63.20, so I might look at the price of a couple of aftermarket options too...

Thanks for all the responses too, have indeed given me a few ideas, it seems most people I've talked to use silicon stuff for sump gaskets by the way.

cant you just leave it like all other datsuns and let the leaking oil form that lovely grit filled sealent goo like it does on all other parts?

either that or let it rust on like an a12 i looked at where it was left in the outdoors with no gasket or goo, he decided to file it flat and bolt it on! either way you wont have to worry about leaks... or getting it off in a hurry.