Ap27 a lot of ppl use the 58 cc heads to make good power. I have herd that a 2.02 valve upgrade and good port work is almost as good as ported humps. The extra compression ratio makes up for a little less flow. Of course a set of 210 cc heads would be make some much bigger numbers and in a vette it will be usable power since its a light car geared and good stall. Too small a cam would also suck.
Gtech is not bad at all. Just got to be fully mounted in the car and not wobbly. Also use the gtech at the track then you will have something to compare once that is done you will find the gtech very accurate tool to test upgrades. It may be off a little but it should be off the same everytime. I have used them and found them to be dead on once compared to track and finding it was always 3 mph off. Timer is very accurate and is good way to do road testing. Iphone apps wprk too but they are not as accurate as the gtech or other real deal solutions on the market.
Never used the vericon but have used a radar gun turns out cops see someone on the side of the road with a radar gun they tend to stop and ask alot of questions just as you come flying past. LoL which can lead to my second peice of useful adive about the wind from your car blowing a state troopers hat off.