coz i added teh super charger = more air, i needed more fuel into it too, so had to up the fuel pressure too. dont need to do that with out the super charger.
trimatic 3 speedo auto, aka traumatic, can be modifeid to handle a lot of power, manual valved, was it not shifting by it self, you have to put it up a gear manually for it to change, hold it into gear for as long as you like then.
yeah basic mods, are bigger air flow in, via the cold air induction, air scoop.. and more out, a bigger exhaust, 2.5 was very loud mind you, i wouldnt go any bigger than that, i think standard is 1.75 or 2" anyway, i cant remember, it was a long time ago...
make sure everything else is in good order, good spark, good fuel and you be right... change the fuel filter too..
the real question is, its not speed you should be worried about, its keeping that speed, via handling, driver skill etc ;-)