Scott -
I installed the boost sensor directly under the big cast iron (or aluminum) 90* intake feed from the intercooler plumbing. There is a little fitting you can unplug and the sensor for your gauge should go right in. I think this is the same port RFitz mentioned. Don't forget to use some thread sealant (I prefer the Teflon sealant in a tube verses the teflon tape on a roll). Trans sensor is a bit more difficult. On my rig the front outlet (pressure) line is where I figure the temps are the hottest, and about 5 inches along the line right out of the trans case is a factory fitting and a thermosensor. I simply unbolted the line at the case fitting (it will dripp a little, so plug the outlet fitting with a rubber vacuum plug), unscrewed the factory sensor, installed a T fitting (male-female-female, left-right-down), and screwed the factory sensor and aftermarket sensor in place. Worked slick. I had to very slightly bend the 1/2 inch line to clear the side of the case housing where the pan bolts up - don't use too much force to do this as you could kink the line. I also had to use a pipe wrench to hold the factory line port still to unscrew the thermosensor - the weld doesn't look strong enough to hold the wrench pressure to remove the sensor.
Also, My rig has a factory-installed aux cooler/fan, so my plumbing might be a little different that without one. I have only ever seen this version.
If you want to install an oil pressure gauge, install a T fitting in the block right behind the power steering pump (this is where the factory pressure switch is current;y located - you will have to use a short brass 'extension' first as the T fitting won't clear the block outer wall as you screw it in. Then install the factory and aftermarket sensors and you're good to go.
Hope all that makes sense - if not give me a holler and I'd be happy to talk about it.
- Sam
(805) 735-9408