Funny you should mention old pickups......as I had a built 350 in my '67 Chevy short-wide pickup with Doug Thorley headers, glass packs and exited right infront of the rear tires. I ran true dual with no connector and had the raspy, pop-pop-pop deceleration noise. Once I added in an "H pipe" (not an X), it improved driveablity, made the exhaust sound much smoother and quieter and got ride of interior noise. I was so glad I did it. I recommend some sort of crossover, just for the benefits. Just my experience.