1. Get whatever bolt fits the ear. I thought they were all ½"-13 UNC but
maybe not. I have a 75 block in my garage. I'll check it tomorrow if I
can remember.
The twisted-off bolt should not be too tight unless it is bottomed out because
it was too long and screwed in too far. If you can get a left-handed drill
you can probably drill till it grabs and comes out. (Not too big a drill!)
2. The volume in the bulb needs to be large enough to keep pressure in the
whole length of the tube even if some condensate drips back down into it.
Bigger bulb = better stability.
3. Probably not too much difference. If there is a difference it will show
up in slow, heavy traffic driving on hot days.
4. Yes. The nuts where the pipe bolts onto the manifold want to be tighter.
5. Pierburg pumps rarely give problems with too much pressure. Other brands
and especially unmarked pumps tend to be more problematic. Use the ¼" spacer
with a gasket on each side. Same pump is used on the B30 so it has sufficient
volume capability.
6. My manuals all say use motor oil in M41 and M410 so that is what I use.
If there is 90 in there now and it is working OK, keep it. Maybe change to
lighter oil when you feel it is time to change.
--
George Downs Bartlesville, Heart of the USA!