I had a mid 2000's Sporstmobile on a Ford E350 and frankly, factory stock it handled like a pig. It's that Twin-I-Beam front end with virtually no castor to keep it pointed in the direction it's going. Unfortunately Ford spent so much in developing that front-end geometry that they had to keep using it far longer than it deserved in order to recoup development and tooling costs.
Fortunately inexpensive spacers on the rear axle, which otherwise has a narrower track than the front wheels, (Cheaper to use a stock axle than tool up and build one that actually fits!) improved handling from terrible to occasionally annoying in a crosswind. .
I ordered the conversion with the spacers but in the excitement of taking delivery didn't realize that they had not been installed until I was 1200 miles away and freaking out about my poor choice of chassis. Point is, on my way back from that trip I got the spacers installed and had first hand experience at how much they improved handling for relatively little cost. They are easy to install, basically bolting onto the hub then the wheel is bolted onto the spacer's studs.
