Holley 1850 replacement carb
 

Putting together my 396/325 BBC for my 1965 Impala. I want to run the Holley carb which came on the 1965-66 396/325 (also with Quadrajet.)

Wouldn't I be able to use aoff the shelf Holley 1850 600 CFM carb? Same Throttle bore diameters and Venturi size as a original Holley.

Would I need to ask NHRA if they would add it as a replacement carb? Has anybody ever tried this?

Re: Holley 1850 replacement carb
 

That's a trick question. There isn't a listed replacement on the NHRA site for that carb. The Holley part number for the one you want to use is 0-1850 and the first paragraph of the replacement carb section of the Accepted Products document reads in part "Holley dash numbers are accepted unless otherwise noted".

Talk to Quick Fuel. They have a long list of carbs that NHRA has approved as replacements and never added to their documents.

There's no listed replacement for the Holley listed on my SBF, but QF has the SSR 585 listed on their documents as an approved replacement. More cash, which I'm out of, but nice carb.

Dale

Re: Holley 1850 replacement carb
 

I have a 66 396 Q jet core

Re: Holley 1850 replacement carb
 

Tried to send you a private message. Says your full. Clear it and I will send you some info. Or e-mail me...I can't get the format to post here.

Re: Holley 1850 replacement carb
 

I personally took and 1850 side by side with a 3140 (the #'s correct for my 66 396) to Pomona last year and Bruce B said No Problem its OK!. You can PM me for details on this app. I already have Dyno'd this carb on a 396/325 back to back with a 3140. Also talk to Scooter Vester at Quick Fuel. He has a approved carb as well.

Re: Holley 1850 replacement carb
 

I'm not familiar with this at all. Could you tell me; isn't the Quadrajet bigger?

Re: Holley 1850 replacement carb
 

Since when does a center pivot dual line Holley get to replace a square bowl single line Holley? Your photo is questionable if that is the 1850 replacement.

Re: Holley 1850 replacement carb
 

Yes the Quadrajet is Bigger BUT it has its issues.Bigger does not always mean better. Holley is easier to tune.
As for the Holley, We have run it in several versions. Changing the bowls and metering plates is legal as far as I have been informed. The unit on the engine was the one looked at by tech.We ran in 5 carbs that day on the dyno. If for some reason someone wants to protest it changing it only takes minutes. It is just easier to tune this way. I have multiple carbs in different configurations- Centerhung dual block,Center hung 1 block 1 jet plate, Side hung transfer with jet plate. The thing was to get a tuneable secondary and adjustable floats. After all is said and done it is still 1562 x 1562 /1250 x 1313 and says either 3140 or 1850 the rest just bolts up no different than jetting, the main body is untouched and still legal. I have seen ALOT worse go through tech. Besides the Quick Fuel is legal too, Have you seen that?! It looks 10x better than the swapmeet/ebay stuff we are playing with.

Re: Holley 1850 replacement carb
 

I understand the easier to tune aspect, but isn't the Q-jet 750 cfm? Seems like a lot to give up. Maybe I'm thinking of a Thermoquad...

Re: Holley 1850 replacement carb
 

dyno tested holley intake 6948, vs 3948 q-jet intake same 750 holley carb on both intakes . 6948 holley intake down 20 horsepower on 425 horse 454, steve