I ran mine from the heater core, behind the engine and into the intake.
You can kinda see it here:
So far it's working well. I have plenty of heat through my heater core and plenty through the intake.
...and I think it looks nice and neat too.
I tried plastic T's but they're junk. Never could get them to seal up right and one even cracked on me. I spent the money on the brass fittings from Lowes and have had excellent luck with them. They weren't cheap but they're holding well and look pretty good too.
it's a 250 but you get the idea.