UPDATE:

I picked up the 400 last week. I traveled 1300 km round trip to get it. But my brother and family are near where I picked it up so had a nice visit as well.

I pulled the valley pan and measured the lift of the camshaft with my dial indicator. came up with the specs for a Summit 2801. Probably the most common camshaft for 400s. I read it is similar to the 068 with higher lift.

The engine came complete including Qjet headers, all accessories. All for $550! Very happy!

I put the specs for this engine and my 350 in to Desktop Dyno. the 400 measures more low torque and less peak HP. This can't be right.

I'm wondering if I will really see a marked difference between the two. My 350 is no slouch. I can easily spin (one) tire when I punch the gas. and that is with 2barrel, ST300 and 2.56 gears.