What have I got, I know one is totally different, one has a half tag that says 701200, and one has a full tag with 7023050 and, under that is 83, and 29. I am trying to get around 300 hp with a 79 mopar 360 out of a motorhome, with a 340 torker elderbrok intake, and a 5spd. What carb rebuilt would be easier to tune and run good? I am looking for gas milage, but I also understand that it is controlled with the right foot, to a extent.
Step one: sell those old Rochesters on ebay. Step two: Figure out what kind of carb to buy. You might have trouble with that intake and that transmission, but it might also depend on what rear gearing and camshaft you are running, what kind of vehicle it's in, etc. Having that info might help someone help you.
I would sell them carbs if I new what they were. This set up is in a 1937 Dodge truck, boxed frame IFS, and a Jag IRS rear with 3.31 gears. It is the stock cam in the motor which should be a rv grind, but have not checked it. It will be my daily driver. I thought that the intake would work good with a 5spd?
A single plane manifold is not going to give good mileage. A spread-bore carb on the stock 4brl manifold should work well. Port injection would kick butt. Those old Rottenchesters should be quite valuable to the right buyer. Top and bottom views don't tell the story on application. Right and left sides pics should show the differences and someone may make you an offer. Whatever carb you use make sure the power circuit is closing at cruise vacuum or mileage will suffer and use a dist with working vacuum advance.
Looks like a Rochester 4 jet (4GC). http://www.carbkitsource.com/carbs/tech/Rochester/4G-index.html I like them, but not for making 300HP. http://www.carburetor-parts.com/Rochester-4-Jet-Identification_ep_401.html http://www.hotrodders.com/forum/rochester-4gc-carb-cfm-rating-20811.html
The Rochesters you have were and are excellent carburetors. However, they do not have a proper fuel curve for a 360 MoPar engine; and parts, while readily available mail order, are not locally available (depending on your locality). The one with the 6 digit tag is missing a number. The tag number should be 7 digits. As far as getting 300 horsepower from the Rochesters, the 7023050 did more than that on a STOCK engine (just not on a Mopar). Jon.
7012000 is the carb #. Well the quest still continues for a carb, so if anyone has a carb that would work for me, and trade for one of these let me know. As far as the intake, it is the one I got so for now its the one I will use for now. I can't imagine that I am going to get good gas milage the first year of driving the truck anyways.
Are you going with the 5speed? If not and going with a torqueflite you will want to source out a carb that has provisions for the trans throttle presser linkage.
I disagree with the poster who said mileage will suffer with a single plane manifold. That is not my experience and a brief chat with Cliff Ruggles with confirm that. It's all in the jetting and really understanding how a Q-jet works. 20-25 mpg with a Qjet and a single plane should be readily doable. Cliff has written a couple of books on these carbs and he is great about answering the phone and talking about the carbs and their uses.
As mentioned earlier in the thread, the best mileage will be obtained using a spread-bore carburetor and spread-bore intake. If it were mine, I would be looking for an O.E. Chrysler 360 spread-bore intake and a 1974 Chrysler 360 Carter TQ. Maybe even a 1975 carb. I wouldn't want a carb newer than 1975 because of the built-in smog emission. Jon.
So keep the factory intake I have and take the Carter TQ off of me 1973 400 dodge motor, and I will have a good set up. I am always open for ideas. I am trying to do this on a budget, so having the parts helps. How much for the parts to rebuild this carb.
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