I have a 67 toronado with the 425, I did the top end on it, after re assembly it ran fine. then I noticed that the two rubber gaskets on the front and back of the block pushed out on each end. I took it apart and replaced the valley pan again, same thing happened. the rubber gaskets start working there way out as soon as the engine gets to operating temp. I am using gasket sealer and torqueing the manifold bolts as the manual states. Any ideas what could be causing this, I am thinking that maybe I need to replace the bolts, is it possible for the bolts to have stretched or something,

 

Use a thick bead of silicone ditch the rubbers

 

Yeah, this always happens with the rubber gaskets.

They are worse than useless.

... Made you buy two more intake sets than you would have, though, so I guess they served their purpose.

- Eric

 

Agree with the above.

I have read that the gasket material "The Right Stuff" works really well for that application. Apply a bead across the sealing area where the rubber seal would go instead of using the seal. I have also read that a bead of RTV has been used successfully, as has the rubber seal glued down with 3M Super Weatherstrip Adhesive (leave the top dry with no sealant).

 

thanks for your help guys. I replaced the turkey tray today, threw out the rubber ends and am letting it sit till tomorrow night before I start it, and change the oil