1971 slant six 225 no spark or weak spark at plugs?

Yep! That does not surprise me at all. You have to be very careful buying aftermarket parts anymore. I've used a WVE part before & will never use them again. Even a long established company like Standard has crappy parts a lot of times. Most things, even aside from car parts, are made in CHINA & it's junk. I would rather have stuff made in pretty much any other Country. I have been very happy with the parts I get from NGK/NTK, think spark plugs, sensors & the like & the more expensive stuff isn't always the best.
Glad you got it fixed though.