Differences in Q-jet vs 585 Holley vs 4GC

[Mark Yacavone]

Originally Posted by Ernie Neal

The 585 was used on the Corvette 327/300 66/67 a 585 was also used on the 350hp engine in 65/66 it had jet plates on both ends. The carb we are talking about has 1 9/16" throttle plates. Don't confuse this carburetor with the 66 chevy II and others with 275 hp and a holley it only has 1 1/2" plates.

We use the 67 327/300 comb in the Sunfire my son drives. In our case the holley is better due to the hp factor, but may not work as well in all cases.

Ernie Neal
SS 354

Yes, the 66 540 Holley should be rated about five more than the 4GC, but so far, NHRA doesn't want to hear about it.