>This may be a simple tuning issue<

Finally! Forget what the timing is set at. Advance the timing about 3’ to 5’ and see what happens.

>It sounds mean and tough<

At an OC MD cruise week, a passenger said to his driver that my car “sounds like a pussy.” To the raiii clone 9-owner who may be a member here: What do you think about that pussy sounding engine? Anyway, if the timing is late, it allows lots of fire to exit the exhaust ports, and mixed with the fire is a bunch of noise because the bang is happening after the fuel leaves the cylinder.

>just the nature of the car with low acceleration<

Same engine I have in my car, 350 slush box, 3:36 screw. A quarter throttle leaves a pair of 10’ slabs, and it asswalks for quite a while if I shift to second while the engine is low in the powerband. Idle to wot; the car sits there and white smokes the tires,. Yes, there is a significant learning curve on the throttle to get hooked up.