There is a discussion ongoing at the S-series.org 60 deg V6 forum regarding this very subject:

http://forums.s-series.org/viewtopic.php?t=13925&sid=914eb7d45db5002d3ef64f098bd6693a

You could use a TBI-to-4bbl adapter atop the 4BBL manifold top, however you'd lose EGR. The 2-bbl manifold top retains EGR but you'd need a special-made adapter to mount the TBI.

The thing that gets me is the uneven runners from side to side. Without having the matching Edelbrock TES headers (the S-10 headers won't fit a Trooper), I can't see how uneven runners would benefit.

Personally, the stock TBI manifold, bored out, and maybe port-matched to the heads, probably flows as well or better than the funky Edelbrock. Maybe a little Extrude Honing to smooth out the runners?? It'd be interesting to see airflow 'stats for these intakes.

If I were going to look for a different intake, I think maybe an Offenhauser Dual-Port might be a good choice. Unfortunately they aren't made anymore so you'd have to find a used one somewhere. Saw one on eBay once but they are few and far between.