T-8280 Preheater Upgrades

[Dawn]

Reading through some of the game board repair forums, it seems that the T-8280 Preheaters have some quality control issues, but are a favored entry level unit. There's talk of relplacing the stock thermocouples and doing some mods on the power supply to increase the spec of these units. I've found a company that offers these units already modded at over double the going price, but haven't found any info on anything besides replacing the thermocouples as a DIY project. Can anyone point me to a source on these mods?