Rear Turbo Woes--Consultant DER Powerplant for 337?

[Timcote1960]

Hi All,

My rear turbo in N639GC totally crapped out and the turbo shop says the housing is unusable for a rebuild. Rear turbo part number is 406610-9022. Turbine housing itself is 407169-0007 but that doesn't matter, neither are available ANYWHERE.

What is possible is to mount the front turbo into the rear. Chatted with a Skymaster-only mechanic today who INSISTS that front/rear turbos are identical save minor bolting dimensions. Not certain that a Designated Engineering Representative (DER) sign-off is required, but because it is a different part number, my A/P and I are trying to hunt one down not far from MD.

Does anyone on the 337 forum know a Powerplant DER rated for a P337G for a field sign-off near to Maryland? We have the Directory but don't want to start out blind. Tried Owen, not helpful.

Tim Cote