I was reading the Torque Pig article on the 500 build up and they mentioned blocking up the EGR passages. As another smog power sapper would plating this port cause damage to engine from the higher temps or pinging? Could the knocking be offset by adjusting air/fuel mix? I don't think the older CADs had it and they were OK with a bit more power.

The older BBCads having more power doesn't have anything to do with EGR. EGR should be off at WOT and thus not make a difference in power.

Ask the guys at GM powertrain and they will tell you that a properly tuned EGR-equipped motor will make more part-throttle power than without. The EGR cools combustion and allows more part-throttle timing advance. This is why the motor will ping and knock when the EGR valve goes bad.
Like Dave said, the EGR is closed at WOT - when the engine needs nothing but clean air.

The reason that "smog" cars had so much lower power output was because of dropped compression, smaller cam profiles and the horrible pellet-style cats that they used back then. Heck, most of it is the cat - replace it with a modern style "monolith" converter. The current hi-flow converters cause next to no restriction if properly sized.

Thanks, I already replaced cat with new one. No emissions test, but got one anyways. Should have went to dual exhaust when I did it originally. Live and learn. Thanks, for now I'll work with the 8.5? not 10 or 11.5:1 ? I think i have the smaller 76cc heads too.

Hey, even without an e-test, there's no sense to go messing up the air more than need be.

I've spent some time under my SDV podering how to put true duals under it and have never found a great solution without sacrificing clearance. The gas tank is set over on the pass side, so both pipes would have to run down the drivers, except there isn't much room between the frame rails and the tranny.
What I have pretty much settled on getting is a 3" single system. It should be more than enough for a mild street motor with loads of torque.

I'd stick with 8.5:1 compression the way gas prices are going thesedays... Filling up at over $3 for premium can get frightening (and I know many other places are over $3 for regular!). According to The Cad Company, 10:1 compression is only worth 20hp and 10tq on a stock motor. Not trivial, but when you weigh the cost of gas against that...

If you do bump the compression, keep it to 10:1 unless you want to run race gas. 11.5:1 does not work on a street motor unless you are running a ton of cam duration and are very careful with the tuning.

Bump it to 13.2:1 with Al's forged pistons (and rods) and run propane. Or if you're gonna stick with gas just mill .030 off the heads if you ever have them off, bump it to around 8.75 or 8.8:1.

That's right, I'd forgotten about the propane option! Won't early 76cc heads and late flattop pistons put the CR right around there as well? I wouldn't think you'd need a forged bottom end to run a mostly stock motor on propane.
Propane is still $1.999/gal here. Technically you'd have to pay road tax, but there are ways around that. Of course it also has a lower energy content. Have to work out the $/BTU...
Know any good places to get a propane carburetor? They don't seem to be a big item thesedays.