[Pappyx3!]

Check your wheel cylinders to see if they are froze up, when they freeze up you feel like your applying enough brake that it should stop but the wheel cylinder can't actuate the brake shoes enough to stop efficiently. Went over mine not long ago and 2 of them were froze. I went ahead and replaced all 4 wheel cylinders, shoes and hardware. Stops good now.

Yes you can upgrade to power brakes rather easily, there is info in the FAQ's regarding the parts/processes to do it. Make sure you check out CaptnFab on this site for his info on booster mounting brackets.

Welcome to the forum! How about some pics of you project?

Good Luck!