[rchalmers3]

[quote=Dougal;3396912]The capacity of the two engines is similar enough, that the main difference comes down to the revs.
The 2H revs about 10% more which gives you another 10% possible air consumption.[quote]

The revs you refering to are the governed engine speeds, right? What if (as marting indicates in post #8) the driver has lower speed driving characteristics and needs, and is willing to sacrafice a drop off at the high end? Would that change your recommendation or is it your opinion to put the margin in anyway? I'm tuned into this because it sounds like his vehicle and driving needs are very similar to mine, and I'd like to install a system that works as intended the first time. My guess is he would like to experience boost as soon as the throttle is cracked and experience boost at 1k rpm.