Has anyone done the ATR Stage 2 heater box kidney plate install?

[Intercooler]

I was looking to get the fiberglass piece to fix a hole in mine but they no longer carry the special heater core for it. Anyone try this with a standard heater core?

 

[6APPEAL]

I talked with Dave Fiscus when he did his. The stock heater core is too long. He went to a radiator shop and they ordered one from measurements taken if I remember correctly. HTH
John