I'll start by saying I don't know anything about carburetors.

Last summer, my boyfriend bought a 1978 Pontiac Trans AM with a 455 bored-over to a 472 ... forged internals, blah blah blah .... well the sucker runs like a bandit (ha ha) - so long as you don't put your foot all the way to the floor.

The car has a QuadraJet carb which most of the people I've talked to say that's the problem. When you mash the pedal down, the car falls on it's head and then takes off like a shot. ...

Any help would be greatly appreciated.... pictures would be even better!  

The secondary doors can be adjusted so they don't flop open. On the pass side of the carb there is a screw that a spring wraps around. Under that screw, facing down, is an allen head screw that is the set screw. Loosen the allen head and turn the spring screw a little tighter. Retighten the allen head. Be careful not to over tighten the spring screw or the spring may snap.

If your car needs more air loosen the spring instead.

You can also get secondary metering rods that are smaller and will give you more fuel, but I would start with above first.  

Thank you greatly!

I bought a cheap q-jet carb from a 1980 Chevelle off ebay a bit a go so I could tear it down without risking damage to the TA's carb ... for educational purposes only.

Well, the thing's sitting on my desk right now and I think I found the allen and spring screws you mentioned. Weather permitting, I'll try tweaking the TA's q-jet over the weekend... and I'll post up the results!

... and if this doesn't work we'll talk more about metering rods. *groan

Thanks again!
~Jenn  

Those metering rods are really easy to change. One screw right on top of the carb, in between the secondary doors. You can change them right on the car.