Just an observation from someone who at one time came on here often and stopped. I stopped because of the responses I got were typically wise ass comments. When I would get answers back on questions, rarely was my question answer but I was given suggestions saying "You should do this and that" and typically it was way beyond what I was looking to do. the sachasm back towards me in e mails I got based on questions I posed was the final effort I made in educating myself on my BB build. Take it for what its worth.
On the other hand of this. No offense to the original poster. But beyond your asking "Who has definitive expereince with these heads on a BB build" you have gotten some good infomation from very expereinced people here,,,Johnny O, Pat and Erik have all given you basically the same answer in different ways. These guys all have much more expereince that you and I for sure. ... Even if you think their advice came acrossed in a poor manner. It seems like YOU DONT WANT to hear/accpet what they are saying and are fighting and waiting for someone to tell you WHAT YOU WANT TO HEAR, (that they will be great heads) rather than the truth. You came acrossed just as sarchastic in your comment "Maybe I should go to a 4x4 web site to get smoe info. Im sure you could...cause thats what those heads were made for towing, torque, pure daily driver kind of heads..not performance.
No offense, no flaming..just trying to maybe help you come to realization. Good luck with your build!
I really dont understand your dilemma. budget is a probelm is the impression Im gettin from you...so put the heads on and have fun cause for around town driving IMO you will have more fun with the peanut port head than those rectangular ports. Save you coin and get a set of 781's with proper valve and port work and put them on later.