[tdangle]

Originally Posted by Tom

Did you change jets and adjust the 670 beyond just turning screws?
Otherwise this could just be a fluke because the newer carb has the right jets to meter correctly.

Actually I did. Had it tuned on a chassis dyno. They rejetted the carb and commented it really likes to run rich. Worst $550 I spent. I told them I was more concerned about drivability than max power, but didn't turn out well. Since the out of the box jetted borrowed carb works so much better I'm still thinking EFI might be a step up.