Good choice on the Dynomax Super Turbo's. I can't think of anyone who has them who hates them. I put a large body one on my Dakota. It even sounded Ok with the V6. Until the weight of the huge 3" tip broke the casing where the pipe goes in, I just added a hanger to support it. It sounded nearly stock inside, till I opened my window. Outside sounded very good. Now just noticeable inside and pretty loud outside. I love the Hooker Aerochamber mufflers on the 88. They are on the loud side but the very padded Brougham interior must make a difference. I moved the whole system to the 70S and drone city. Maybe because the interior is less padded and the X pipe touched the hump on the crossmember and resonated. Either way Super Turbos for the 70 with full length Chinese Stainless headers. I didn't realize they kept the dash the same through production but it is. No surprise your car was stolen, older GM's were always a target and super easy. And yes, your car is a masterpiece and the million hours spent on it to get that way proves it.