holley used to make an economy replacement spreadbore carb to use in place of a q-jet, numbered 4360 "economaster" I think, (not to be confused with the 4165 "spreadbores"). it is a 450 cfm carb (four bbl talk)with mech. secondaries. 1-3/8 primary. 1- 7/16 secondary bores. They were not popular as they didnt get too much better economy than a stock q-jet ( same sized primary barrels) and nowhere the hp (DUH dropping down from a 750 cfm carb to a 450 cfm carb-what do you expect). But its a dandy size for a 250 six and more compact than a 390 cfm holley design. Had one on my '67 std shift p.u. with headers-it was a replacement for a 350 chevy q-jet. They do make one to replace the q-jet on a buick 238 V6- that one has some extra idle circuit work on the secondaries. Thats the one to get. I got some holley literature about it and duplicated these v6 mods to my v8 model and it turned out to be a good streetable carb on my "cold" clifford intake. its milage didnt break the bank either. I have seen some on e-bay. These are a good, yet unknown carbs for 230 to 305 inch motors. Ran that setup for 2-3 years before I tried a common 1850 (list number) 600 cfm vacuum secondary. It was ok and smooth because of the vacuum- but the 4360 was the real sleeper. Not many at swap meets anymore, they came out in the mid-seventies. These shoehorn right in between the 390 and 600 sizes.
Last edited by preacher-no choir; 06/21/1102:20 AM.
