Good luck splitting them because they are mounted with JB weld or some king of epoxy, best to try to find a single. or you might be able to use a 360-C and bore out the back to fit a 380 butterfly. #60-C is a factory alky carb.
What size is that 360C and what engine have you used it on before? Might be interested. You can pm or email info. I don't check all the forums so frequently lately.
I think you'll find the 360c is a way to small a venturi and bore. I've measured the 360a and its larger than the c model. And it won't bore to a 380 bore either. The 181 hr carb or equivalent is the next best option.