I agree with SF. I have seen popping out of the trumpet many times on IR cars. When cruising the throttle plates are open so little and the engine rpms are great enough to accentuate any synchronization issues. Get yourself a synchronizer and double check that it is even or relatively close to on all clylinders. It typically wont show on a wideband because the wideband shows an average of several cylinders. Too little timing at cruise can also cause some popping.
PANTERA INTERNATIONAL
A DE TOMASO CAR CLUB
Presents the De Tomaso Forums
The On-Line Meeting Place for De Tomaso Owners and Enthusiasts From Around the World
Clicking on the banner will take you to the sponsor's website.