Put old ass hard as a rock tires on it, it will lay it out then. Mine did when I got my car (350 2brrl).
Bone stock low compression 73 Buick 350, just cut off the exhaust to let it breath a bit, new plugs and wires, fresh Q jet rebuild, 12 degrees initial timing, 34 total. plus 8 degrees vaccum advance on a ported source. Ran good, still have this engine and it looked brand new inside. Actually the crank is in my friends stroker 370 inch Buick 350.
That set up should do some tire roasting? My 70 350 GS had less go fast goodies and smoked the posi hydes easy when you stomped the go pedal. The lighter distributor centrifugal weight springs definitely help get timing in fast, but it needs to be timed right too. 94 octane helps as well Also how's the health of the QJ? 50+ yo carbs are not always up to that task. I had a lot of problems with QJ's over the years, even with professional rebuilds. They wear out. A Healthy carb is mandatory for maximum lift off thrust.