cleaning ICM

[89reattaWI]

I’m new to working on cars and engines so firstly, thank you all for insight and feedback. You guys have the best advice in my opinion compared to videos. I always try myself, before asking.
 

But the pictures i’ve attached is my ICM and i’m not sure how to clean it. I used a wire brush to get some off but it didn’t do anything for what you see there.

[2seater]

That is pretty crusty looking but I would use a coarse scotchbrite pad to get the surface clean. It doesn't have to be shiny but it needs to be smooth for good ground and heat contact. Electrical cleaner might help. Just for clarification. the first photo is the bottom surface of the Delco ICM and the second is the top of the mounting plate? If that is the mounting plate, it looks different than the style I have seen in the past?

[89reattaWI]

it is the mounting plate i wonder why it would be different. the mounting plate is from a 2004 chevy impalas L36. does it go on reatta the same way it came off of the L36?

[DAVES89]

I use sandpaper and brake cleaner. I don't believe that plate is going to work. GM for a couple of years used a transition plate as they were converting from Magnavox [square coils] to Delco [round coils]. This transition plate has the three screws sticking out of it so it can mount on the Reatta bracket. Then there are 6 threaded holes in it for the Delco unit to screw down into the transition plate. The 6 original screws on the Reatta are not the same size as the 6 Delco screws are.

The transition plates are getting hard to find.