I have these on my van, and they fit with no modification whatsoever.

Hector
1990 Carat

> Actually, they are zinc rods inserted into a bolt that fits in the engine
> drain holes in the cylinder.
> They are larger than the stock plugs, so you have to drill and tap the
drain
> holes.
> It is difficult to do this on the left side of the motor as the pushrod
tube
> blocks part of the drain hole.
>
>
> Todd
> '88 Westy
>
> "Sean B." wrote:
>
> > I haven't looked into it too carefully, but Fast German Auto touts a
> > product they call "Z-sticks" which (I believe) are basically zinc head
> > studs. They say that these are supposed to help with the corrosion
issues.
> >
> > Sean B.
> > '90 V'gon, "Happy Bus", pseudo Wolfy
> > Torrance, CA