It is a2bbl. I'll pull off the exhaust manifold and see. It's a1970 with the front cross over tube to a single 1 1/2" exhaust down the passenger side with 2 mufflers!!!
A 1970? You’re good on the heads. No worries there.
You’re looking at 1-5/8 headers. I suggest a 2-1/2 exhaust pipe size. An “X” or “H” pipe to connect each side. To help keep things as quite as possible, a Dyno Max turbo muffler is probably your best bet. Or a Walker sound FX. The longer the muffler, the quieter it’ll be and since it’s an RV, quite inside while cruising is one thing but at rest is another & something I’m sure you’ll be after.