I have a question about the coolant bypass/steam tubes that run between the heads. What gasket or o-ring should I use between the tube and the head? I bought the metal/rubber seals that BT sells, thinking that was correct.

However, when I actually looked at the tube, it used O-rings and not the metal seals. There is a pocket that the oring sits in, so I'm not sure if the seal will work. Engine is a '05 5.3.

has anybody seen this before?

 

Your best bet would be to go to the dealer with your vin# and get the orings there. They will more than likely have them in stock and cheap. I have seen some after market stuff use just a o-ring and some OE stuff use a metal gasket with a rubber seal made onto it where the fluid/vapor flows.

 

Yes. The early engines used the rubber seal with rubber impregnated into it.

The later ones went to an O-ring and the base is machined for it.

You need to use the correct ones for your application.

12551933 Early style flat with rubber
12602541 Late style O-ring

Early 4 port spider crossover is discontinued. You have to retrofit to the late style. only thing available for the early style is the bolts that hold it down and the gaskets.

11588714 (M6X1.0X30) Bolt Early style

12604711 Is the front cross over Late Style
12602540 Is the block plugs for the rear with O-ring late style
11514008 (M6X1.0X30) Bolt Late style