Bill is correct about the Holleys. I guess my prejudice is showing. These things are an absolute bear to modify, so I don't generally consider them at all.

However, they can be used where other units cannot if one has a hood clearance issue, as the Holleys are at least an inch shorter than the other units.

Jon.

Good carburetion is fuelish hot air
The most expensive carburetor is the wrong one you attempt to modify.
If you truly believe "one size fits all," try walking a mile in your spouse's shoes!
The Carburetor Shop