Either that, or find one of similar proportions, maybe like an '86 Chevy P/U, and cut and modify it to fit. I was looking at some pics. in Truckin' mag, and that '86 Chev might be the way to go. You'd really have to find one and measure it up.
2 forum members at vannin.com custom made there own billit grills for prior to 93 year dodge vans, 'laylowcustoms' and 'Cobalt dream' I think are there handles, laylow is a member here also and u can prob find pics of his van which is for sale. Cobalt is only a member at vannin.com as far as I know.
According to the stull website they do have a grille available for 79-93 vans. The website says "78-92" but more likely 79-93. However, the grille/headlamps changed in 86 on vans, so I'm not 100% positive that this Stull grille would work.