Thanks for detailing your build and letting us know what kind of results you are getting out of the work you are doing. I am looking for a Suburban for our Summer outings and have a few questions:
1. How hard is it to do the TBI upgrade and what is the cost you spent on parts?
Sorry forgot your other question.
Kevin, the whole TBI upgrade with air filter will set you back around $600 But these items offer proven lower end power and better MPG. One guy over on the CK5 forum has been testing these parts for almost 3 years one part at a time and combined trying to see whats snake oil and what really works. The items I chose have all gained mpg or power. I did some similar mods to my Jeep Cherokee and noticed bottom end and MPG gains.
All your doing is letting an "airpump" breath better.
These things come off the line with a Fuel pis range of 9-14. Gm said good enough its within spec. The adjustable fuel pressure regulator will allow me to up it to the proper 13 to 13.5lbs. The "powerplate" is a TBI spacer with bored holes to match the TBI bored holes and are blended together so that one side can scavenge from the other if/when needed other wise one side of the motor starves out.
Also in the pile-O-parts is rebuilt matched fuel injectors. rebuilt is obvious but matched is another thing. it will allow for more consistent burn again not starving one side or the other. a cheap trick i learned was to take a timing light and aim it at the fuel injectors. I noticed my drivers side FI was more of a drip then a spray. I am still waiting on the Hypertech Powercharger aka the "Salad bowel" you basically cut out the center section of your stock air cleaner and install this allowing the air to curve more graciously down to the TBI instead of it having to do an abrupt 90* down turn. The skeleton looking black piece of plastic is a Fuel injector pod spacer. It raises the injectors a 1/4" to help atomize better.
Hope this helps.