I am using one 4 conducter gfs crunchy rails humbucker in bridge and one 2 conducter stock fender fat strat neck pickup, guitar is charvel strat type with pickguard cut for single humbucker but body is routed for two humbuckers and one single coil. So i will have to cut pickguard for neck pickup. It has one volume and one tone pot so i wanted to wire both p/u's in series for heavy rythym work only is this possible? it has no switch and honestly i dont want to add one therefore both buckers wired in series for an always both on would easily drive any amp over. i have other guitars for clean work so i know it would be a single use guitar purpose. thank for any tips.
You could try (using clips or terminals to make the temorary connections to make sure it works before you solder):

2 conductor ground to ground and hot to 'ground' of 4 conductor (according to my GFS = black)
connect red + white
send hot (green) to vol, vol to jack as per
connect tone to vol as normal

That should give you 2 HB in series. If you need I can draw a (bad) diagram for you (but they are a pain...).