I'm more into Pontiac's but they all operate the same so I'll throw in my .2 cents. By the sounds of the car it is a show quality car? Like maybe aftermarket pullies? Is there a chance the water pump is simply not being turned fast enough? To big of pully on there and it may be to slow especially if there is a small crank pully.

A car I once had would suck the upper radiator hose shut.It may happen with either.

Is the pump flowing the right direction?There maybe an issue with the flow thru the radiator.

To get that hot that fast I would think the water is not getting out of the block fast enough (or at all).

Is the gauge correct?

 

Whatever came of this? Any news?

 

the water pump on 351w there two types one made for serpentine and the one for v belt they turn in different direction