Ran an Edelbrock cross ram on dyno a while ago. Package ended up around the 600 HP range IIRC. Responded very strongly to having one inch open spacers under the carbs (plenum is super shallow...). It also needed a crazy amount of jet pulled out - carbs were a pair of basic 750 DPs and they were surprisingly linear on A/F after pulling something like 10 jets (!!!) out. Scary as hell to tune like that, but I just kept following the A/F, the power numbers, and the plugs until it got happy...