yep complete dash out job. massive job!!!!!!!!! i had a air con company do mine and pretty sure it was just under the 1k mark for parts and labour ( if i remember correctly )
Think you may have the same problem i had in my BH, it was a heater core. Pretty sure it was bloody expensive to fix too. If it is i have the new heater core i replaced as i ended up stripping it out later - only prob 15hrs old.
i had one on my BH but it was for a BH, was very nice i thought def not "loud" but a slight increased "rumble"
but will still come down to what else you have done to your exhaust
ill see if i can get a pic for you, and its not really a sale as i dont really mind if it goes or not its more like a favor as im just not using it atm.
ill take a pic soon and text it to you