Mrviper would be the expert on this but I don't think he is on the forums much anymore. I had and have seen other mod SRX and Viper "ported" cases where all of the additional material has been removed very much like the Red Head crankcases are. I don't know how big an effect porting the cases in this way had but it sure didn't hurt and we all know a mod ported and piped Red Head engine is a great performance engine.
The other tripple tripple sleds of the era like the XCR 800 did not have the additional material either.