Does a cross ram wide base air cleaner seal to a regular cowl hood or do you need to trim something to make it fit? Do you need a special hood like the fiberglass ones on ebay. How did they do it when the dealer installed them when ordered

The underside of the hood is oval-shaped, to match the crossram. I suspect if you tried to modify a standard hood to fit the crossram, it would look like a standard hood modified to fit the crossram. I think a few early hoods were steel, but most were fiberglass. My advice is to save your cowl hood, and use a fiberglass one. (paint both, if not already painted) That way if you ever want to go back, it's a much simpler job.

so when the factory sold them all got a new hood and painted it?

so when the factory sold them all got a new hood and painted it?

you could get an open element air cleaner with the x-ram that fit under the stock hood...

The original cross ram hoods were not available from GM, they were made for SCCA race teams only. They have an opening under the cowl that matches the shape of the air cleaner base.

so a "normal" cowl hood will not seal? Fit? Close? ...unless I use a low base air cleaner that does not seal to the hood?

The low oval air cleaner will fit under a flat hood if you modify the hood bracing as shown in GM instructions 3953866 that had you cut off 7 3/4" length of the right brace and on the right side from 3 3/4" foward of the right rear brace forward until the flange ends.

I've never seen an adapter to make a single carb hood fit a 2x4 cross ram setup. But they make an adapter to use with a 2x4 hood on a single carb motor SBC or BBC.

I have a flat hood with a cross ram and I didn't cut anything off the hood.