I like this kind of thread!
What you're lookin for is just what I've been doing. The best BOMBing 466 is the 93-95(the start of the NGD series), they have almost the same P-pump as the Dodges. They are basically a bigger bore of the 6BT. They(93-95) also had a roller cam, but not sure when that started. Next better ones were the 86-92's, they had a Bosch A-pump, and pretty good BOMBability, but had a real long stroke & smaller bore....less rpm range. Forget about any older, they had the rotary pump, low booost & burn real dirty.
Columbus, Sheids, and Hypermax all make some wild stuff for these. Save money by making your own fuel plate, grind the stock one down to a #0 profile(there's Dodge threads somewhere that show how). Then, use a 3 or 4k gov spring kit, but not sure yet if they share the same valve springs. Top it off with some laser cut delivery valves.
Dont go by the measurements IH gives, they use front pulley to the back of the bellhousing. The bellhousing wont be in your firewall....much. Another note, they have an SAE #2 pattern, and you can use an adapter to an SAE#3 for more choices & smaller flywheels. The 3 is smaller than the 2. They fit in a Super Duty the easiest, and OBS the next easiest. Here's a shot of one going in a 74 F250(I talked him into doing it), and note the new firewall & how deep it's set back:
http://rides.webshots.com/album/558...es/trucks&track_action=/ViewActions/FullAlbum
Then here's mine:
http://community.webshots.com/album/558845243ReTuWq
I've heard on another site, the Eaton RTO6613 shifts real nice & it's not too terribly big.