Installing intake

[classical glass]

I have a 427 FE side oiler, just completed a complete upper rebuild. Valves guides
springs, seals, harden seats etc. everything was going great and smooth until it came time for the intake install. It doesn't want to seat perfect on the heads. There is a rocking motion hence something is keeping it from seating flat. I noticed the head gaskets are sticking out slightly from the top of the cylinder head.I had the manifold checked for flatness and straightness and everything is fine, so the problem is somewear else. Is it possible the lower portion of the manifold is just hitting the tops of that gasket? I'm installing a ford 2- 4 barrel intake which was the original intake that was on the car. I believe I seen somewhere that there were some tabs that needed to be bent because of this issue. Maybe not. Any input or help would be appreciated.
Thanks...

[blykins]

Yes, have to bend the tabs down. I take a little ball-peen hammer and knock them down against the block. Make sure the factory dowel pin is not in the block near the front china wall as well.

[classical glass]

Originally Posted by blykins

Yes, have to bend the tabs down. I take a little ball-peen hammer and knock them down against the block. Make sure the factory dowel pin is not in the block near the front china wall as well.

Thank you,

[Danr55]

Have you had the heads and manifold match machined? If the.angles are not the same or you use a different thickness gasket the relationship may not be correct.

[Gaz64]

Originally Posted by Danr55

Have you had the heads and manifold match machined? If the.angles are not the same or you use a different thickness gasket the relationship may not be correct.

Yes, any change will warrant a manifold machine.

Block surface, head surface including angle milling, head gasket type, inlet manifold gasket type.

Gary