[Tim Corcoran]

The 67 GTO came with a twist on vented oil cap in the valve cover on the drivers side and a rubber plug on the passenger side. I would like to remove the plug and put a push in breather in the passenger side. The valve cover on the passenger side has a 1 inch hole. Does anyone know where I can get a push in breathe for a 1 inch hole. Can's seem to locate one. Thanks

[mgarblik]

Summit racing has a variety of the push-in breathers they say are for a 1" hole. If the hole in the metal cover is 1", the grommet diameter may make it too small. Take a look and see I guess.

[OCMDGTO]

Pretty sure Spectre makes ones for both. I ran them for years on my old 400. Only downside is there is no baffle.

[78w72]

Originally Posted by Tim Corcoran

The 67 GTO came with a twist on vented oil cap in the valve cover on the drivers side and a rubber plug on the passenger side. I would like to remove the plug and put a push in breather in the passenger side. The valve cover on the passenger side has a 1 inch hole. Does anyone know where I can get a push in breathe for a 1 inch hole. Can's seem to locate one. Thanks

1" breathers are pretty common, this link is for all 1" breathers at summit.

https://www.summitracing.com/search/...ver%20breather

[rolling money pits]

This will be of no help…other than to let you know it’ll be a PITA finding an aftermarket breather to fit a factory VC hole.

If the hole is same size a later factory covers, you could find a grommet, but no breathers to fit, been there did that years ago.

IIRC aftermarket breathers are all, pretty much, designed to fit 1 1/4” holes, once a grommet is in place. That math doesn’t work for our covers.

I guess it’s possible to source some factory breathers from another brand … Ford, Chrysler, etc, they may have the proper nipple size?

[hgerhardt]

Years ago I machined an adapter to fit one of those 1-1/4" push-on K&N's.

However, after a 20 second search, found this: https://www.knfilters.com/us/62-1160...ilter-breather

It's got a 3/4" tube out of the bottom which will fit the factory grommet that was used for CA cars in the RH valve cover.

One thing I'd do is add a 2" long standpipe on the end of the filter to minimize the oil mist into the filter. That's what the CA tube did, and that's what the LH valve cover breather (non-CA cars) also had.

Photo below is that grommet: part number 9776721: https://butlerperformance.com/i-3164...rar-vcgr1.html.

[Schurkey]

Originally Posted by Tim Corcoran

The 67 GTO came with a twist on vented oil cap in the valve cover

WHERE is the PCV valve plugged-in?

Why would you need more than one breather?

[Tim Corcoran]

I found a breather and grommet that works on the factory valve cover that has a 1" hole. For the record you can't just buy a breather for a 1" hole as you need to account for the grommet, and you need the correct grommet too. You need a grommet with a 1" OD and 3/4" ID. Then you need a breather with a 3/4" OD nipple. Ames has two breathers that will work and the correct grommet. Ames part number N222BB and N222BBC. The correct grommet is P/N N220A. Thanks for all the responses but all I had to do is pick up the Ames catalog and problem solved.

[78w72]

Sorry for the link to 1" breathers, your post said you needed a breather for a 1" hole.

Plenty of breathers for 3/4" holes...

https://www.summitracing.com/search/...ver%20breather

[rolling money pits]

lol. Either all those weren’t around, or I didn’t look hard enough, when I needed one.

Hell, the chrome spectre job has a review with it on a Pontiac engine.

[grandam1979]

When I was running double breathers I used 2 LH valve covers made it easy.