Yes I have seen some people weld in tubes or half tubes to notch the frame on some cars. I don't know if this is as strong or not, for myself I'm chicken to do it. But the chance of a crossover pipe might be compelling to you. They say by not having a crossover cobra sidepipes give up 40 or 50 hp. Ha! I WISH my setup only gave up that much.
I know the hurricane frame has a bolt in X member under the transmission, and like most cobra frames has significant side to side members in front of the rear wheels.
Transmission removal will be hindered by pipes in there too.
Hmm... I'll have to get out there and look at a frame again before venturing much more of an opinion.
I have not reworked my exhaust yet so I don't know anything more about the hushpowerIIs. I think I'm leaning more towards spintech "Sportsman Street" # 3333 at the moment. I wish someone would flow test mufflers so you have some idea what you are getting. I'd really like to use dynomax but the 2 1/2" ones are too wide to fit, and the 2" ones are obviously a cork.
http://www.spintechmufflers.com/spin...ntechindex.asp
Chuck