Is a MSD coil any better than the gm coil on my 97 502? Will it make a hotter spark or dwell longer? they are only $50 so if it helps i'm on it.

Not if your current ignotion is OK. Sure they can make 40+ kV, but your firing voltage will depend on wire resistance, plug gap, fuel mixture, and cylinder pressure and that wont require half that.
I've found $12 external resistor generic GM coild work fine on most applications.
Gary

Don't waste your money. Sure that high voltage rating looks impressive, but that's open circut voltage. The average sparkplug fires at around 6kv. Once the plug fires, the voltage no longer climbs, it's all current after that. If you're not having ignition problems (plug fouling, etc.), it won't do much for you. I had an MSD 6A in my jeep with the blaster coil. The coil lasted six months before the primary side opened up. A year after that, the box died. That's the last time I used MSD. Every one I know who ever used one had it die on them, that's why I won't put one in my boat.

My $.02

it might idle better on older plugs but that's it

hey kennyo, I've got one you can try if ya want. Next time I'm in town, I'll bring it with me!