Boy! 2nd time I have read through the build and it is so cool! And I think I see something strange about you old dyno sheet. The Clifford 264 hyd. cam is capable of 5,000+ rpm and the 270 is capable of over 6,000 rpm. It looks like you have the 264. Which gives .518 lift. I've seen the Clifford 270 cam used with the lump port heads and it worked just fine. A guy had a 250 with a 194 lump port head, 1.94 in and 1.60 ex valves, flat top pistons, Clifford 270 cam, offey intake and langdon headers. 500 cfm holley progressive 2 barrel. And it made 285 horse on the dyno! Plus it pulled a 4,000 pound chevelle station wagon over 100 mph! You can see it on youtube...don't have a link. But I don't really think the carb has to much to do with it...I seriously think your dyno spec were wrong...not sure but it has haunted me since I saw it!
Anyway, cool truck! And glad the 6 is running good!
