Greetings Baxter650,
I was just made aware of your build the other day. VERY nicely done. With an avatar name of 'behemoth60'... you can probably guess that I am a fan of built 60 series.
Having built and run a 53" tired 60 series with a 'high output 3B' running lots of boost, my advice to you is to be concerned with heat.
My experience is that the 3B's limitation to power is it's inability to shed heat effectively. In my set-up, I had the new high-nickel head which has better water flow, and a very large chevy 4 core radiator. My boost gauge only went to 15 lbs, and my engine would pin that gauge with every touch of the throttle, so I don't really know how much boost I was making. With all that boost, the EGT's were well under control, but the problem I experienced was that the coolant temp would slowly climb and climb, and I would have to stop wheeling in the middle of a climb or mud puddle, just to let the engine temp drop. As a trail-only rig, this was a minor inconvenience, but if I had any inclination of actually running on the road, this would have been a critical problem. That engine did, however, make, like, one million horse power. 3B's are amazing engines.
Keep up the great work. This is an inspiration to everyone and I think you're doing everything right.
Have you considered getting rid of the leaf springs for something a bit more modern?
Peter Straub
Calgary, AB
Rocky Mountain Land Cruiser Association
TLCA #7571