I am looking for a plastic fitting, that fits into the rubber gromet on a 502 valve cover, to allow for a hose up to the breather. The only ones I can find are 90 degree fittings. I want a straight one. Basically looks like a PVC valve but is plastic and hollow. Anyone know where I can get one?

I know exactly what you are talking about and I'm 99% sure that I have got them from O'Reilly's in the past. Check with your local store.
Eddie

Napa or Oreily should have them. If not, you can get them from Merc for $20 each. They were used on carbed 500hp's and 525SC's

Those are about the only places I have not checked. I will check them out tomorrow. Thank you both for the info.

I'm going to need one too, so please post where you found one. Also, my other valve cover has a grommed for a PCV valve. Should I use one?

google heater hose splice.. http://www.bing.com/images/search?q=...4-18&sp=-1&sk=

I found those heater hose splices. The only problem is the ones I found only reduce from 3/4' to 5/8'. I was trying to go 3/4" to 1/2'.

I ended up using a plastic fitting that is used in a plumbing application. It was 3/4" and threaded at one end and had a 1/2" hose barb on the other end. It had a hex type center section to help with screwing in the fitting. I ground off the threads of the 3/4" end and then ground off the hex to make it round. Painted it black and it works perfect.

The piece I used is called a 3/4 to 1/2 hose barb to male adapter.

I think I used something similar on a different set of valve covers. I left the threads intact and used Ultra Black RTV - figured the threads might help the sealer get more "bite".