Gear needs to be a tad more steep, at least with the 572, I don't know yet with the 604. So, from a 4.10 to a 4.30, I think it would help as they like higher RPM's. The timing is less, from 33-34 total, to 30-32 total. They like big carbs, 1250 and perhaps even bigger or 2. The converter should stall at least 6000, and 6200-6500 is even better.
The upside of these things are common intake/exhaust rockers, much higher flow, bigger cams are effective, they don't need as much compression but respond to more, and from what I hear they are very NOS friendly.
The downside is, don't try getting any info from Indy, they are more expensive than the B1 stuff, special headers, pistons, gaskets, etc.