Exhaust difference- 550/650

I'm looking at exhaust for my 82 550 Maxim and I'm only seeing a 4-1 from Mac ,but no 4-2 from anybody. The dozen or so books that the speed shop looked in has a ton for the 650 but not for the 550. Is there any difference in spacing and height between the 550 and 650? Will a 650 4-2 bolt on to a 550?
I do plan on pods or airbox mod and a dyno tune after to get the mixes right again. Any guesses on power gains? I think the bike is rated at 55hp stock.
Thanks

 

650 pipes won't fit on a 550. Different spacing and bigger diameter pipe.

If your going pods and 4 to 1 you will gain some performace, but not without some re-jetting.

 

Unfortunately, I think the MAC 4-into 1 is your only commercially available choice at present. I have a 4-into-1 Gemini system that I love, but they are out of biz. I don't particularly like the MAC because I'm not impressed with the workmanship, (compared to the Gemini) but the price is right. At any rate, from the little I've read a 4-into-1 outperforms the 4-into-2 anyway.

 

I'm not impressed with Mac either, had a Mac exhaust on my truck and it didn't last long or fit to well.I want to stay with a 4-2, don't like the way 4-1 looks. I guess I get the paper and pencil out a design a more flow friendly crossover. I know people that have a car exhaust shop that can bend and weld stainless. Does anybody happen to know the firing order for the 550's?
Thanks