Finished the 7747 to 7427 swap about a month ago (recommend) followed by installing a three wire vortec MAF and separate IAT sensor (HIGHLY RECOMMEND the 7427 / MAF setup for TBIs!!!!) Truck runs so much better than before but I've got two issues that I haven't been able to solve since swapping to the MAF bins.

1. 700R4 TCC: Since swapping to the MAF, the TCC in my 700R4 has not worked. Originally the $0D_MAF.xdf file I was using didn't have any TCC scalers or flags present. I copied and pasted some from another $0D non MAF mask, but it still hasn't worked. If I throw my old speed density chip back in the TCC works fine. In the 7427 pin out swaps I've read, I saw some debate on which pin to put the TCC on. I'll go back and look at my notes to see where it is now, but I know I moved it from the original pin I first had it on. But, again, with the speed density chip in, TCC locks up fine.

2. EGR: All the MAF masks I find already have the fan hack in them. I need the EGR to function in order to pass emissions. Disclaimer, I have not had the truck tested again since moving to the MAF setup. Tested it two weeks ago before the MAF swap and it failed due to HCs being above the state limit. Truck was running BLMs of 118 - 120 @ 2500 (2 minutes, part of Nevada's testing procedures) and idle BLMs were around 123. I plan on testing it again today once I put new plugs and plug wires in the truck. Truck does all in town driving and the AC plugs (R43TS) might be too cold.

Last question is for educational purposes. I see the differences between xdf files others have built in the forums. How do you edit/build them? I was using right click copy the copy xdf parameter to clip board, then open the xdf file I was using and pasted it in. Which hasn't worked.

Big thanks to Eagle Mark, Fast355, 93V8S10 and Dimented24x7 for all their TBI posts.