I really don't understand the appeal of the Type IV motor unless you build it BIG and do something about the restrictive exhaust ports.
If you are only shooting for 150 HP, you can achieve that easily with a 2.0 liter Type 1 motor and have half the cost of the T-IV. Plus it will be lighter.
A 82 X 90.5mm Type 1 with 9:1 compression, Engle FK-8 cam (or similar), 44 IDF's and a nice set of CNC ported heads would make 150 hp all day long. In fact, CB Performance sells a complete kit of all brand new parts (including case)...out the door for $3,600 US...spend $600 to have it assembled and you are ready to roll.
And before someone jumps in and starts preaching that the Type IV is going to last longer...BS. There is no reason that a good T-1 with reasonable compression and a new case will no tbe bullet-proof if assembled correctly and driven by someone who knows not to lug the engine.
Anyway...my uninvited 2 cents...
. Great project!