And more torque from more inches will only make the converter seem more sluggish on the street.

I fought this issue on my 540. It was just too 'mushy' below 3,500. I wanted a snappier, crisper response at low engine speeds. Like when I was cruising and driving around town. I tried PTC twice, but I wasn't happy with the results. I ended up sending it to UCC, back when Lenny was still there. He opened the converter, called me and said there wasn't anything else off the shelf he could do to tighten it up any more.

BUT! He had a couple of tweeks he could make and had some suggestions for me to do on my end. Now that helped a noticeable amount. The car moves off better and is almost as crisp and responsive as stock. And it cost less than $350. Lenny's the man! Or was the man, anyway.