I have a 69 442 convert with 4 spd tranny and 400 engine. Right now I have a Rochester Carb 7029250NF. My question to the board "Is this the correct carb for this engine? If not what is the correct carb for this car?

Thanks
Mike

 

1969-
350 7029250
400/455 7029251
455 Toro 7029252
400 M.T. 7029253
400 W-30 7029254
350 W-31 7029255

http://www.442.com/oldsfaq/ofcrb.htm

From 442.com

Looks like you have a 350 4BBL Carb, The 253's are around, I'm sure somebody on here has one to sell or try Sparky's Carbs he may have a core.

 

Thanks for the info

Yes it does appear that I have the 350 carb. What problems should I expect using this carb on the 400?

I know the carb was purchased for the car before I got it. I inherited this car from my dad several years ago.

 

Your carb can be rebuilt with all the correct components for your application.
You'd pay a premium for a correct 7029253 carb, and unless it was newly rebuilt, you'd have to rebuild it anyway.

 

So the 7029250 can be adjusted to work on the 400? Would the retro parts be available in a kit form or would I need to purchase the components separate? What changes would need to be done in order for this to work correctly with the 400 engine?

 

I can't tell you the exact differences, but it probably involves jets, metering rods, and maybe idle cams and the sorts. A good carb rebuilder would have the specs to know what to change.
Rebuild kits won't have the components you'd need to change.

Your carb may work sufficiently, just not optimally with the 350 carb.

 

I've been doing a lot of research in this area the past month - I have a '69 carb on my '68 442 and am checking whether it is worth my time to try and alter it.

There are three configurable differences between the cutlass/442 carbs in 68 and 69: Jets, Primary/Secondary Needles, and throttle bodies (carb base where the butterfly valves controlled by the throttle are located). The jets and needles are available from many carb oriented websites - stay AWAY from ePay for these. The throttle bodies - not so much.

You can find the specific details on the jets and needles at Wild About Cars. I have been unable so far to find any info regarding the throttle bodies, other than they are available only as component parts, probably from Rochester, and maybe some aftermarket/repair shops. GENERALLY speaking the 350 carbs had slightly smaller jets. MOST of the needles are the same size from carb to carb within a given year.

The airhorns and float bowls are generically the same within a given year. The main differences in vacuum passages are in the throttle body.

Pics are two pages from the WAC Carb info section, as a teaser - highlighting is mine.

Hope this helps.


Rich

 

I have a 69 4 speed carb that is rebuilt, replated, flowed, etc. Ran very well on my 70. It does have a service date, but for the price you would be hard pressed to find a better one. IMO...

 

Here are my scans of the '69 Cutlass/442 carb parts. As in my last post, the differences are the jets, rods, and throttle bodies.

 

Thanks, Rich. Good information. I'm surprised that there is that much difference between a '68 and '69 carb of the same application as alike as the engines are. I'm sure the differences are minor at best, and it is entirely possible that the '69 is an improvement even when used on a '68. (Another year for improvement)

I'm amazed at how many people are more concerned about the number that is on a carb (and other other components) than they are what is inside the carb. Same goes for insignificant date codes for that matter. Especially when there are few truly original carbs out there. They vast majority have been rebuilt with no way of knowing what the guts are. That's why there are a lot of "numbers matching" cars out there that run like crap. Fine, if that's what floats your boat. Fortunately, you don't need a "numbers matching" carb to make it correct. The info is out there, and most good carb rebuilders have it and *can* do it right.

Face it, there were a lot higher % of performance car carbs that were swapped out for aftermarket carbs.