i have a 95 cobra and i run a 180 all the way and i drilled a 1/8 hole in the top to disperse air. as for that heater tube u should ditch it to clear the clutter out of the engine bay and go get a 1/2 npt pipe plug to seal the intake once u get that broken tube out. u can try
www.50resto.com if u really need that tube but i dumped it when i put my edelbrock manifold on.