That intake (cast iron, 2v) is a monster and I'm tired of lifting it in and out (yes, 3 times since I've owned the truck for various reasons) and still having it leak.

Also, while I'm at it, would I really get anything out of putting on an aluminum intake and 4v carb on a stock 351M? It gets 10mpg right now with the 2v and has good (better rephrase that as "satisfactory") performance (DON'T LAUGH) for what I use it for. Its an old beater truck and gets treated as such. But, I'm just thinking aluminum would be easier to man handle back onto the engine and since I just bought that holley to replace my 4100, I have an extra 4v already...

use a thin coat of aviation gasket maker (brown sticky stuff) on both sides of valley pan...use thin side rail gaskets that come with valley pan....use end seals or RTV...let set a few hours before starting engine...I know the frustration...did my aluminum intake four times (using various combinations of gaskets, valley pans, side rails, etc.) before I finally got it right...