How about this for luck. I went to a freinds house the other night to work on the door of his 55 chevy,and after we gotdone we were sittin around bench racing and mentioned that i was lookin for a small Holley carb and he got up and brought out a box from under his work bench with a extremely clean lookin carb in it.I looked at it and noticed it was quite a bit smaller than a 600 and it was a vacumm secondary and he said "here,take it" so im thinkin that i might have scored a 390 but just to make sure I called Holley the next morning and the tech guy said it was a service replacement for a ford but it looks like every other Holley 1850 that ive ever seen.Turns out that its a 450 cfm vacumm secondary and even though it was super clean i went ahead and rebuilt it anyway with a Holley kit and new power valve and it was just as clean on the inside as the outside. It has 58 primary jets. How do you think this will work on a stock slant with a HyperPac and headers and msd.

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Ive got a slanted attitude and a heavy right foot.

The 450 should work just fine.
It may need a little more squirter jet and a higher rated power valve.
Try the carb out first then adjust it as needed.
DD

Nice score! 58's will be a good place to start , but I'd think a pretty stock moder might want something a little smaller.

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Official Cookie and Mater Tormentor.