Rocket Richard

Hey,
I just caught a CL ad where this guy is parting out a 75 olds 98 with a 455 engine. I wouldn't mind getting a 4 barrel carb and intake to put on my 425 (I have a 66 Dynamic).

Do you guys know if this should work? Assuming that he has a stock 4bbl 455 engine, would this be a decent carb?

-Rich

joe_padavano

Yes, it will bolt up. Carb will be configured and jetted for emissions, low compression, and EGR, but it will run as-is, just not be optimized.

BILL DEMMER

you'll likely have issues with connection of the throttle rod, as the '75 carb was actuated with a cable. and that carb. will be seriously lean on a '66 425. you may have to go as far as modifying the idle circuits too, to get it to idle right.


bill

joe_padavano

I'm going to disagree a little, Bill. The Qjet is amazingly flexible. I've got a 1986 Chevy 1 ton dually with a 454. I replaced the crappy Holley that was on it when I got it with a Qjet from a 350. I did nothing to that carb other than rebuild it. It may not be optimized for the 454, but it runs fine, idles fine, and it is not "seriously lean". The 76 455 carb, if not previously rebuilt, will probably have the stupid idle screw caps or plugs that need to be removed, and will likely need to have the secondary air valve spring adjusted, but other than the throttle linkage (which also really isn't that big a deal), it will work just fine on a 425. It won't be optimized, but it will be noticeably better than the 2GC.

Rocket Richard

Well that sounds good to me Joe.

I don't know much about olds carbs but it seems strange to say that a carb meant for a 455 would run my 425 lean. And then why would they make a carb that runs too lean? That's not good for the engine right? Plus I understand that there are ways to adjust fuel delivery.

Joe, if I make a deal with this guy I hope you don't mind me asking some more questions on how to set this up right.

Thanks.

BILL DEMMER

you are free to disagree, and maybe you got lucky. absolutely true that qjets are, as you call it "flexible", or as i call it "forgiving". i think the op is going to be beyond the "forgiveness" range. the engines in the era that the op is speaking of, liked their fuel, the later motors were designed to like a "very weak tea" polluted with exhaust gases.


bill