I run a healthy hydraulic roller in my 408 Magnum with an automatic transmission. I used Precision of New Hampton to build a custom 3800 rpm stall, lock-up converter to match my combination. They nailed it. It wasn't cheap, but I learned you get what you pay for with converters if you use a reputable shop.

My car lopes pretty good at idle in neutral or in gear. I would have issues at idle if it were not for the higher stall converter. As it is, there is barely a change in idle speed when I put it in gear. The modern converter is so efficient, I only gain 300 to 400 rpm when I unlock the converter in 4th.