Those are pretty common answers. The place I work with usually won't dyno engines they didn't build since it often turns into a pig pile. He has modified his policy over the years so he'll dyno engines from certain shops that he trusts but it still goes sideways on a regular basis. Not having the correct motor mounts or crank adapters or headers is also a common problem. It can cost upwards of a $1000 to equip the dyno for each engine model and if the customer doesn't want to pay for it then why should the dyno operator. A BB Mopar is fairly common so you should be able to find a shop with the setup you need but good luck if you want your nailhead run on the dyno or a 409 or something like that.

Alcohol shouldn't be an issue but I'd charge extra since it takes time to flush the system out afterwards. You're probably looking at $2000 for a couple of days of testing including switching carbs and fuel and doing multiple pulls to dial in the timing and jetting.