That whole area at the left rear of the engine is a pain to work around. Motor mount, clutch linkage. master cylinder lines and linkage, speedo cable. If Gm had just put the battery and starter there too it would have been a a total engineering snafu. I like Bob's Idea of running both pipes under to the right side where there's more room. I totally agree they should stay together. Putting one on each side makes one a lot longer. I think the idea of one on each side was to emulate a V8 look. Actually on our inlines one pipe is enough and it doesn't have to be a sewer pipe either. My 270 in my 53 pickup has had several exhaust systems in he last 30 years. The best performance (street driven) was Clifford Viper Tube headers,2" pipes to the bumper with class packs and a crossover pipe right after the header flanges. Some said I didn't need that on an inline. The worst setup was Fenton cast headers with 2 1/2 pipes into a 3" collector to a Flowmaster and a 3"pipe exiting just in front of the driver side rear wheel. It lost both bottom end power and top RPM. It sounded hollow and created a weird pressure thing that actually hurt ears if I drove with the window down. It now has the Fentons with 2" pipes side by side out to the bumper on the driver side with 20" or 22" Cherry Bombs. It sounds powerful when you are behind it but quiet enough inside that I'm considering fixing the radio. I can drive with the window down in comfort. A couple of years ago I was in the running for the "Rappin'" trophy at our car show but told them to give it to someone else because I made the trophies and I could just make myself another one. I know it sounds great.
I don't know if any of this is worth any thing but one thing to remember is that too much pipe is possible with these engines. An all out race motor might be different but for a wide RPM range some think a little restriction is helpful.
