Larkja, I too would recommend big-bore SUs for a street car. However,... You do already have the triple setup, and it is very possible to make it run correctly. From your reference to Dave and Andy, I'm assuming you are in the bay area somewhere. So I will share one of my greatest speed secrets with you. Put away ~$400-$500 and call Ken Murillo @ Classic Motorsports in Santa Rosa. He has been tuning my race car for a few years now and I swear by his skill with triples on the Datsun. The cost is a little high, but he does his work on the dyno, and does it right the first time. After installing my fresh engine this year I went to Ken for tuning, he pulled an additional 55hp out of an already tremendously powerful engine. Best of luck.
Michael
Classic MotorSports
(707) 584-3762