Vented oil filler cap for 18V engine

["Steve Shoyer" <Steve@shoyer.com>]

We finally moved into a house with a garage, so I'm hoping I can fix my car and 
get it running again.  The last time I tried to get it inspected, there was oil 
being propelled out of the dipstick tube.  Loosening the oil filler cap "fixed" 
the problem.  I thought I'd replace the cap with a vented one, at least just to 
get the car inspected and legal again.  Which cap will fit my engine?  It's an 
18V, 1980 MGB.

I promise I'll fix it corrently one of these days, really.  Thanks.

--Steve