S&S heads

[BB]

Working on a 2003 engine with a S&S 106 kit . Owner said if he would get on it hard it would blow the dip stick out . Too much crank case pressure .Engine has stock rocker boxes and S&S heads . Removed the rocker boxes and found it has the correct gasket on the front head but a cometic gasket on the rear . This will block off the breather . Looking at the rear head  the breather hole is a 1/4 hole with thread and has a orifice  in it .Thats is the question , why is there a orifice in the breather hole ?

[Barrett]

https://assetcloud02.roccommerce.net/files/_sscycle/2/7/10/51-1108_cylinderheadstc88_20080428.pdf
Here's their info.

[trex]

I'd say the question is why are there two different head gaskets?

[FLDavetrain]

The SnS lower rocker gasket has a breather passage cut out that carries pressure to the breather head bolt area. Someone must have worked on the rear cylinder and used a standard Hd/Cometic type that's obviously meant to cover an Hd head casting. Far as I know only SnS lower gaskets can be used w their heads.

[jsachs1]

The SnS lower rocker gasket has a breather passage cut out that carries pressure to the breather head bolt area. Someone must have worked on the rear cylinder and used a standard Hd/Cometic type that's obviously meant to cover an Hd head casting. Far as I know only SnS lower gaskets can be used w their heads.
[/quote
You can drill the missing hole in a stock Harley Twin Cam lower rocker box gasket. Easy, and works perfectly on S&S heads. 
John

[tdrglide]

I have S&S heads on my 03. If using stock rocker boxes you must use the special S&S lower rocker box gaskets made specifically for this application. Both heads. Otherwise you have blocked off breathing through any head using a stock gasket. The S&S gaskets are also thicker to give enough cross section space to let the motor breathe. S&S rocker boxes use a bit different breathing strategy.

When using stock style rocker boxes I set it up to breathe stock style, including umbrella valves. (Except to atmosphere ). Never blown a dipstick.