i noticed recently now that i am getting closer to the plumbing end of my project that some stat housings and x-overs are plumbed together and some with out. any help on this would be appreciated.

i would assume the type that plumb to one another (bypass) would be more apt to be used with t-stats and the ones that don't use the customized stats (drilled holes) just my thought at 12:30 am.

thanks again,
john