Make sure you get the resonators, resonator mounting hardware and and optics and mounts and if he's scrapping them, get the cathode transformers. I90MRAs dont exactly fit in I90 heads without some work.. Also get the ignitor modules. I have a few spare resonators and lexel style ignitors.
If your putting them in a I90 Scientific head:
I. Magnet is smaller diameter, you need a 3/8" or so thick half moon spacer to bring the centerline up to the cavity axis.
II The MRA magnet water pipe prevents the lid from going on. I had a machinist make me 1" tall lid extender rails to fit the lid on.
III the brewster stem diameters are the same, but the covers need sliced down.
IV, I can whitelight them without them seeing Air. They whitelight very well.
The overall length is line, the mounting bracket spacing is fine, the optics and cavity length are Similar.
Steve
Qui habet Christos, habet Vitam!
I should have rented the space under my name for advertising.
When I still could have...