carbs popping, and bonus clutch question Options

[vitaminC]

In my quest to drive every 914 I can, yesterday I drove a 73 1.7 that has recently been refitted with a 2056 with Weber 40's. The car started and idled fine, and overall drove quite nice. However, when I was on the freeway there was some popping happening in the carbs. It seemed to occur more at a steady throttle vs accel or decel. Any thoughts what might cause that?

And on an unrelated topic, where is the 'typical' clutch engagement point? The '73 seemed okay, but the '71 I drove earlier engaged right at the top of the travel (i.e., I hardly needed to push the pedal) and that didn't seem quite right.

Thanks.