The rod from the engine block pivot up to the carburator when connected to the offenhauser linkage hits the rear fenton header, the rear carb flange, and does not sit squarely where it attaches to the offy linkage. I think the rear carb flange is also limiting the travel of the throttle link rod. Here's a photo:
http://community.webshots.com/photo/109150147/124279908BKHefk I will probably be able to bend this rod to make it work properly, but I do not want to do it right now. Once I get my newly rebuilt engine back in the truck, I going to use the original intake, exhaust, and carburator set up that I know was running well prior to the rebuild. I will have enough to worry about with the rebuilt engine, trany, front-end, brakes, generator, starter, and new wiring harness. As the guy from the show Tremors says "The possibilities for disaster boggles the mind."