Let me just say - I've never seen something so simple make a huge difference. I switched to a Wilson 4 hole tapered spacer. I was a little leary about dropping 125 on something so simple - but WOW. Everything I read says use open spacers on single plane intakes, and for dual planes, use a 4 hole or 4 hole tapered. But wow... This was truly glorious.
I got the motor up to temperature after doing the job - and was sitting at a light and decided - lets run a holley commander 950 data log and wack open the throttle. With no expectations as nothing I ever changed made an off idle difference - this thing starts shredding rubber from idle right to 6000. Thinking no way, maybe the ground was damp/wet/sandy/something - I get to the next light. Again and again consistent no hesitation tire shredding power. I was even from a few mph roll making a turn on to another block and said lets see what happens - normally this would REALLY hesitate with a slight roll out for some reason. Instant power as I stand on it and go down the block sideways - something only previously possibly in rain...
I did notice everything seems to be much leaner now, especially at WOT over 3500. So Ill need to retune - but man - its like a whole new car. Never did I expect something so small to make such a huge difference! Heck - when I first bought the spacer it was merely for clearance - I had no idea it was throwing off my tune.