I have that yonaka catback with a 4-1 header from yonaka and a high flow cat from yonaka basically everything yonaka lol, it sounds real nice and deep not raspy at all.
Spoon sounds awesome
What's your ls vtec build? What's done internally?
Where you from? In my area know a guy that can take apart and put everything you have together for $150 that includes main bearings piston rings, valve stems. Seems like one of your piston rings are failing it's better to just get b16 pistons now and got arp rod bolts so you can rev safely high up there. Your ls rods and crank will be better then gsr it's good tq stroke rod length. Then worry bout cams later.