blown SBC with too little fuel flow below 3k rpm

Could be the blower discharge pattern is making the center cylinders rich and the end cylinders leaner therefore giving you a good average AFR if you're measuring at the collector.

Are you set up to check AFR at each primary pipe, or EGT?

Are carbs mounted in-line or side-saddle? Could be a matter of just using dis-similar adjustments on the 4-corner idling if these carbs have it. Leaner to the center of the blower and richer outboard.


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Turns out I did one thing right (posting for help on this bulletin board). As for everything done incorrectly, or at least needing correction, here we go.
Timing: initial was 12; moving it to 16 (and 34 total) reduced the EGT. Jets: carbs came from Holley with 73 primary and secondary; installed 75 primaries and 80 secondaries. Power valves: came with 7.5 power valves; after finding 7 inches hg at 14.0 A/F in Drive at 900 rpm and 12 inches hg at 13.6 A/F in Neutral at 1350 rpm, swapped in 4.5 power valves front and rear. Accel pump arms: one was bent; adjusted all to .010. Accel pump cams: retained red/maroon pump cams. The result: center pipes no longer glow red at idle. Chassis dyno at WOT yielded 11.5 A/F, RWTQ of 416, and RWHP of 435 (which translates to about 515 hp at the flywheel). Thanks again to everyone who responded with extremely helpful thoughts !

First off. Thank you for responding with the positive results.

Secondly Enjoy