Update: I talked to tech support folks at Ram Air Resto and they suggested I remove about 1/8 metal from the manifold. I went a little further. I removed the swivel bracket and ground metal off both the bracket and the two pins. I ground the pin heads down to almost flat as they are pan head type pins. I also removed approx 1/8 inch of manifold material. Now I have approximately 1/8 inch of clearance. Even after doing this I had to replace my clutch pedal as the lever that attaches the z-bar rod to the pedal broke at the spot welds. Maybe the level bent enough to brake when the swivel was hitting the manifold. Who knows
. The good news is everything is back to normal. Thanks to everyone who replied to the post.