Made my own down-pipes for Hedman shorty headers
I had the same problem with the 340 manifold on the driver's side of my '69 Barracuda (318), P/S, 2004R transmission with TCI adapter). I ordered some super tight radius J-bends (see pics) and cut the J-bends up and pieced it together. It took a lot of time but it wasn't too hard. It would have cost a fortune to have the muffler shop build this pipe system. I had asked the muffler shop (last year) to use 2 1/2 down pipes and never looked at them after picking the car up. When I installed the 2004R transmission I found that they had used 2 1/2" on the passenger's side but because there was so little room on the driver's side they used 2 1/8" with no mandrel bends so it was pretty bad. If I had known about the super tight donuts I would have bought one. The donuts look even tighter than the ones I bought even though the ones I bought had the tightest MANDREL radius I was able to find on the internet.
But your job turned out nice and you'll have very little restriction. Building your own isn't difficult but does take a lot of time.
Most muffler shops don't have the machines capable of making the mandrel type bends and super tight radii so if you don't do it yourself or pay some pretty big bucks to a upscale muffler shop you're just out of luck!!
Treblig