Ford E-series cutaway? Since introduction of the E-450, tire specified by Ford has been LT225/75Rx16E, on 16.0x6K wheels, for both E-350 and E-450. For chassis going to RV manufacturers, Ford put on Michelin LTX M/S, then later LTX M/S2 when Michelin made the materials, tread and construction changes a few years ago.
Although the E-350 does not by weight require LR-E tires, that's what it gets, will lower inflation pressures specified for maximum load. I.E. instead of 80 rear, 65 front, it E-350 will be 60 rear, 65 front.
Tread design can make a difference in handling, particularly if the outer tread bands are blocky, rather than being solid ribs. Rubber compounds also make a difference.
But often, loose handling for the E-series, van or cutaway, is a result of overinflating the front tires to the 80 PSI max on the sidewall, rather than the 60-65 PSI that is appropriate for maximum front axle load. Too much pressure for the load will reduce the front tire contact patch and reduce the turning force available from tire distortion, making the front end slippery.
Make sure inflation pressures are correct, preferably for actual load, but no higher than needed for maximum loads, before giving up on the tires you bought. Chances are, whoever installed them, inflated to 80 PSI all around, because that's the number on the sidewall.