Re: Quick question...need advice!!!
I agree, the 7/8 pipe will work just fine for a stock or near stock engine.
You might gain some power if you go up in size 8''-10'' from the port. A step up to 1'' or even 1-1/4'' can help improve torque and top end breathing depending on the muffler. A straight through glasspack allows the engine to breathe better usually. Gives a nice tone as well.
If more is better, then too much is just enough.
If you can't afford it, build it yourself.