turbo upgrade

i'm about to send my used up k26 off the get the k26/27 hybrid mod. done. i think this is a bigger k27 compressor fitted to my k26 center section and exhaust turbine. does anyone know about this mod. or have any advice on a turbo shop in the southeast. i found a shop in texas, the guy priced a stock rebuild for $450 and the rebuild with the upgrade for $750. please help if you can, thanks.