jpc647

I'm looking at getting my 1972 7042250 Q-Jet rebuilt and putting it back on my car. Car is a 72 Cutlass S 350/350 combo. 3.33 gears in the rear, Edelbrock 1405 carb and performer (3711) intake manifold. The manifold doesn't have the choke tube/egr cutouts. Stock rebuild as far as I can tell. Car idles between 17/18" vacuum at idle. Car has a dual dynomax exhaust system.

I don't know how to tune a Q-Jet. I've only had E-brocks and Fuel Injection up to this point, and I realize how sensitive Edelbrocks are to minor changes. Are Q-Jet's just as bad?

Hobbes in NH is going to do the rebuild. Should I have it build to stock 72 specs for a cutlass? Will it be too lean? I just don't want to spend the money on a Q-Jet to still have it lean. Any small calibrations I might want to consider? I know they have to be pretty much disassembled to calibrate, and I want to avoid that. I will add one of the Q-Jet electric chokes to it.

What do you guys think? It's a driver, I don't go to the track, but do want the best performance I can.

It'll probably be a week or so until I drop it off, but I wanted to give the thread a little time to generate responses. I posted over on ROP too, in case some of you are there, just for some extra coverage.

vette442

Good question. I just had two '72 455 Quadrajets (one for TH400 and one for 4 speed) rebuilt and restored by a shop in NJ that stickw31 recommended. I had them done to factory specs, even though the 4 speed car is mildly modified (like yours, it has been running an Edelbrock carb for the past decade). I'm hoping for great results.

Is ROP back online?!? I haven't been able to access it for weeks and assumed it's permanently down.

Terry

allyolds68

It's been back up for over a month. All the content is gone:

http://realoldspower.prophpbb.com/


I got the rebuild kit and electric choke kit from Cliff's High Performance for my 7042250 and did it myself. At Cliff's suggestion I didn't do any of the performance mods (I also have his book) when I rebuilt it. Cliff said to drive it a while and then give him a call and he'd recommend where to go based on how it was driving. I'm finding that I probably need to jet it up for better WOT (I've got a 455) but it runs incredibly well at idle and around town type driving. The rebuild was very easy. I was lucky in that I was started out with a nice clean carb that had been rebuilt 20 years ago but was never used. I know this doesn't really answer your question but I would be confident that the carb you get back should be reliable.

BTW I saw the post someone wrote back on ROP about the base gasket. The one that came with the Cliff's kit was a lot better (and thicker) that the one I had with my Holley Spreadbore. unfortunately I need every fraction of an inch for hood clearance with the Performer Intake so I reused the gasket I have

pcard

For a street driver the stock setup would be a good place to start. The stock primary jets and rods will probably work fine. The secondary rods, hanger and tension you can change easily if needed once you get it on the car, but with a stock rebuild I doubt if you will have to mess with them.
Once you have it installed and running check the vacuum on the carb idle port to make sure that you are running on the idle circuit (vacuum should be zero at idle).
An electric choke is a no brainer - a few threads exist on how to hook it up.