I have a cranks, no start issue. I think it might be a bad PCM. If I find one online for the exact same model does it have to be the exact same part number? There are a bunch on eBay but I can’t find one with the same exact part number.

The board is encased in rubber so I can’t see it, but the top is all cracked and the rubber is brittle

 

If it's for the same engine/trans combo, it should work.

 

Usually, different part numbers are due to variations in the vehicle options rather than the engines, California emissions aside. For example, the part numbers would be different for a vehicle with cruise control versus one without, even though the engine and tranny are the same.