I have 70 442 with a W30 intake and F heads.
I believe I have a vacuum leak on the intake that I cannot detect from the top.
The ignition has been checked with an osciloscope, compression is great, and tried two carbs.
I have a LM2 A/F set up on the car and it is running lean at idle.
Has anyone had any issues with the W30 intake? Cracks, warping or sealing issues with the tin gaskets?
Thanks,
Joe

 

I have an intake leak now with the tin gasket, from the research I have done on this site come winter I will take it off and use a good standard gasket I got the MR Gasket ultra seal III and then use a sealant on the front and back ends.... I am sure someone with more details and real engine building experience will chime in.

 

Well, the factory used the metal gasket on the W-30 cars with no problems. And yes, it is possible for the aluminum intakes to develop cracks, but it's just as possible that this is just a gasket leak. I would suggest having a machine shop dye penetrant inspect the manifold once it's off.