I did a search but did not find any info on this. We want to build our 1969 Chevelle sbc up to L79 specs. Chevy seems to have used both the 4150 and the 4160 (not only on the 327, but the 396 and 427 as well.)

4150 or 4160? Does it matter? Thanks!

Isn't one a square-bore and the other a spread-bore? If so, then it just depends on whether or not you buy into the philosophy of having smaller primaries for better low speed driveability and economy. Otherwise, they're both Holleys, with all of the good and bad that comes with them, IMHO.

I think that they are the exact same carb except for the 4160 is a production version of the 4150 and has a meter block instead of secondary jets as this was cheaper for mass production... I am going on memory here from what I have read, so get verification before trusting me. smile.gif

4150 and 4160 both are square flanged. The only difference I know of is the 4160 uses a rear metering plate whereas a 4150 uses a metering block.

The metering block you can switch the jets. The metering plate has no jets and thus cannot be re-jetted.

Both Ron and JD are correct. You can pretty much look at the 2 carbs this way, the 4150 is a double pumper whereas the 4160 is a vaccum secondary. If your car is automatic, stick with the 4160, if it's stick, then go with the 4150. Good luck! graemlins/thumbsup.gif

LXS

4150 and 4160 has nothing to do with whether or not the carb is vacuum or mechanical secondary. the difference is ONLY the fact that the 4150 has a secondary block and the 4160 has a secondary plate.

the reason many people get confused is that all double pumpers are 4150 and most (but not all) vacuum secondary carbs are 4160. there were plenty of 4150 vacuum secondary carbs made, such as the original 3310-1. look it up in the holley numerical listings, its listed as a 4150.

Parrydise7

to answer your question, it doesnt really matter which. a 4150 and 4160 will perform the same given the same tune-up. the ONLY advantage a 4150 has is the ability to change the jets in the secondaries, to do this with a 4160 you would have to change to a different number metering plate.

Very true...I have a 4150 taking up space in my parts cabinet...it's not a dp and it has vacuum secondaties.

Originally posted by RatONaStick:
LXS

4150 and 4160 has nothing to do with whether or not the carb is vacuum or mechanical secondary. the difference is ONLY the fact that the 4150 has a secondary block and the 4160 has a secondary plate.

the reason many people get confused is that all double pumpers are 4150 and most (but not all) vacuum secondary carbs are 4160. there were plenty of 4150 vacuum secondary carbs made, such as the original 3310-1. look it up in the holley numerical listings, its listed as a 4150.Duh!?!?! LOL, I can't believe that I forgot about that graemlins/clonk.gif And that's that I had actually read at least 3 books about Holley carbs graemlins/clonk.gif Thanks for catching my error graemlins/thumbsup.gif Man, I gotta do some more reading tongue.gif

Thanks, guys, I really appreciate the info!

Starting in 1968, the L79 used a Rochester Quadrajet (so did the 325HP and 350HP 396). The 4160 carbs used on most of the low horsepower 396s prior to then flowed 585CFM. Not sure about the L79. The Quadrajets flow more, about 750 I think. If your looking for stock appearance in your 69, then a quadrajet may be more appropriate, but if you really want a performance Holley you should buy an aftermarket 4150 or 4160 in an appropriate size.

FWIW you can change a 4160 Holley into a 4150 simply by replacing the rear metering plate with an actual metering block.

Thanks again for the info.

I will be bolting on an 850cfm mechanical secondary dbl pumper on my 454 this year. It sounds like I bought the right carb after all...
graemlins/thumbsup.gif