Greg should know what he is talking about - he owns and runs Phoenix Transmissions, and his team did the buildup on my own transmission, and installed my high stall torque converter.
I can confirm that there are no bad side effects to getting a high stall torque converter from a shop like Greg's where they know how far to go. I love mine. And, as Greg says, the off-the-line performance is so good that powerbraking would be an unnecessary thing to do.
Jim G
