Tec it just don't work that way, 35 psi is also pushing on the propane, so forget about "sucking" anything from your pressured intake. You need a pressure higher than your boost pressure, then what about regulation, unless you rig some trick regulator that compensates for intake pressure....
It is just so much simpler to put it to the suction side.
Check this out, it may help you out
Propane Facts & Comparison Charts
Don`t sweat it, your turbo won`t light off the propane.....it just ain`t hot enough.
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Black 2004.5 air filter upgrade, TST...big wish list....