I am using Aluminum Heads and an Aluminum Intake. I have had trouble getting the intake to seal. I have verified that the angle is correct by laying the intake on the engine and using feeler gauges all around the outside ports and under as well. I have been using the Fel Pro bathtub sheetmetal gasket. with a smear of sealer around the ports. I have heard Chrysler used a paper gasket set in addition to the sheetmetal one when aluminum intakes were used. Is this true and are they available? Thanks.

yes, suprformance (sp) (a sponsor here) has em I believe & 440source does for sure.

Buy the Fel Pro # 1215 440 bathtub kit as it comes with two sets of the good thin composite gaskets and it blocks the heat passage off on the stock type heads with the heat cross over in the stock type intakes also

Cheap, effective, and readily available. Go to most any auto supply and if they don't stock it, they can usually have it the next day.

This x2.

I suggest spraying the gaskets with high tack to keep them from sliding. I also bend the valley trayon the intake off the car to help ease install.

The last time I got the Fel Pro 1215, it did not come with the thin gaskets, just the thicker 0.030" gaskets. But that was several years ago and maybe they supply the 0.015" gaskets now..

Intake manifolds are not clearanced where they cross over the front and
Rear rails. This holds the intake off the head surface.

^^^ for sure mockup & see if clearancing is needed.

I've seen stock 440 end rails that had a chamfer on one side on the ends and not on the other side
I have had to chamfer or shorten them also to make sure they don't hold the intake up from seating properly
I've also seen guys grind their intake manifolds to get clearances to the end rails
Bottom line is to check them and fix as needed

How do your bolt holes line up? If the heads/block have been milled & the intake/head faces haven't been milled enough, the intake will sit high on it's own....basically, the intake bolt holes will be higher up than the head bolt holes making the bolts hard to start & the intake not seal. You can mill the intake to fix this. This is the situation I had on a motor & adding the paper gaskets only made it worse (couldn't even begin to start the intake bolts)

I've never liked the bathtub gasket by itself; using tin snips, I trim the bathtub gasket just outside the embossed ridges around the ports and use a thick composite gasket to do the actual port sealing. This way the bathtub acts as a valley cover only.