I Think I Solved My Problem .....

[George House]

.....Lots of frustration...removing and reinstalling new Langs exhaust manifold numerous times only to have humongous exhaust leaks. Finally I saw the reason. The new copper crush washers didn’t even get crushed. I’m using an original aluminum “high volume” intake manifold painted black and held in place using the half manifold clamp (2) method. The last time I removed the exhaust manifold I spied scratched paint on top of the horizontal aspect of the intake. (Ah Ha moment) The exhaust manifold casting appeared to have factory grinding all around the circumference. So let me take off a little more material from the bottom of the middle 2 exhaust manifold ports where it strikes the aluminum intake...
It works now !!..The 4 exhaust manifold ports completely covers up the 4 glands, is now touching the block instead of the intake. Best of all, no mo exhaust leaks !!

I describe this in hopes it may ease other’s frustration

[speedytinc]

Not the intake manifold?
The repop aluminum hi volume rear intake is extra thick & typically needs some grinding to fit a stock exhaust manifold.

Good deal you figured out the problem.

[RajoRacer]

It's the oversize of the intake as John eluded to - I've installed several & all had to be ground down.

[George House]

But the intake manifold is Original ‘13-early ‘14 aluminum and I chose to grind on the thick repop exhaust manifold.

[speedytinc]

Original manifolds are not normally a problem. You were correct to not grind on it.
I was not aware of an issue with new exhaust manifolds, but, I have not installed a current new unit.
The older issue manifolds fit fine. The only other exh manifold with issues were the Argentina repops from the 60's & 70's. They were extra wide, making for clamping issues.
Good to know the new exhaust manifolds have issues.
I imagine trying to get a new hi volume intake manifold to fit with a new exhaust manifold will double the grief.

[RajoRacer]

My apologies for not catching the " I’m using an original aluminum “high volume” intake manifold" which I wouldn't consider "high volume" - they're just aluminum - I have 2 on T's.

I've also recently installed a couple of the exhaust manifolds from Lang's with no issues regarding interference.