[The_Bishop]

I didn't have timing issues after I threw out the POS accel HEI I had. Went to a completely adjustable MSD billet distributor (Not the HEI version) and 6AL box with a nice short curve that started around 14 degrees and ended around 34-36, all in by 3000 or so. (It's been *years* so I might be fuzzy on specifics.)

I had a box-stock 750 vacuum secondary. It was a POS. Hard to get the balance right on the secondaries opening; they were either too damn fast causing a bog or not open fully. Swapped that one out for a 650 double pumper. No bog on WOT, but fun, fun, fun with pig-rich idle and part throttle operation that took a lot of screwing with to get close to right. Got tired of fouling out plugs with that disaster and moved to an Edelbrock 750. Had zero issues. It was almost perfect out of the box.

Holley's don't (or didn't; I haven't messed with a carburetor in a *long* time) handle part throttle transitions well. The power valve is a sledgehammer fix to part throttle transitions; it's on or off and not linear. It was designed as a 'race' carburetor, so part throttle operation was secondary to WOT mixing.

Meanwhile, the Edelbrock is a lot like a Carter AFB, which was an OEM street car carburetor. It was designed with part throttle driveability and economy in mind. It uses a linear needle for low vacuum enrichment, not an on/off valve. By picking the correct needle and spring setup, you can control how fast and how much enrichment you're getting.

Believe me, I used to be able to tune carbs and distributors. I was the go-to guy for it amongst my friends. I have since discovered fuel injection and can now tune without getting my hands dirty, so I'm out of touch with the latest in 'barely controlled leak' design in carburetors these days, and ignition can be controlled in a vastly superior way that doesn't involve vacuum pull offs, weights and springs.