Upgrade Q's and Brake Light Q's

[92GMCstepside]

I have a 92 gmc stepside reg cab with a 4.3L v-6, i want to know where i can find any information about swapping in some vortec heads. I have heard that you can get up too 50 more HP with vortec heads. And my parking brake light has come and wont go off, the truck does not have abs, the light will come on and blink 3 times pause for 1 second, then blink 2 times, and then pause and repeat. This has me stumped. Any thoughts or suggestions would be a great help. Thanks
Andrew