Going from 4 barrel to 2 barrel carb?

Question

I have a 1973 Chevy C10 pickup with a 350 in it. I would like to change out my 4 barrel carburator to a 2 barrel carburator and I would like to know the best and cheapest way to do this.

Answer 1

You can get a adapter plate to fit under the carb so you don't have to change manifolds, that way you can change back anytime. Have you thought of just disconnecting the 2 rear barrels? You could try it this way and see if you like it :)

Answer 2

You can figure that that biggest carb for that engine is 550 cfm to 600 cfm. Your other problem is finding a 4 barrel intake for a 360 engine that hasn't been made for many years now, this won't be easy and which ever way you go it will cost you some money. If you really want more horsepower then the way to go is to put in a more popular Ford engine like a 351 Windsor or 351 Cleveland, even these two won't be too easy to find nowadays. Another thing to think about is that the 360 is a truck engine with a steel crankshaft that was built more heavy duty that something like the 351 engines. If you go with a different engine and plan on spending some money, then you may want to consider a proven combination carb, intake, and cam from somebody like Edelbrock. You would want a package that's set up for bottom end or what's known as maximum power in the lower R.P.M. ranges like 1500 to around 4000 R.P.M.

Answer 3

The problem with best and cheapest is that the two do not necessarily go hand in hand. When pricing options, in this case cheapest is not that much less than best. To properly go from 4bbl to 2bbl, you would need the following: Intake manifold, Intake manifold gaskets, Carburetor, Air cleaner, Air filter, and Air horn gasket. The air horn gasket is the gasket that goes on top of the carburetor where the air cleaner sits on it. It is not an absolute must, but it helps. Also, the accelerator linkage bracket sometimes is different from two and four barrels. That is the bracket that is bolted on the left or driver's side of the intake manifold that the accelerator linkage runs through. Some of them have square holes, some round. And you may be able to reuse yours. There may be 2 different locations, one on top of the other on the one you have depending on whether your engine was set up for cruise control. If you have an automatic, then you may have that one. If you have a 3 or 4 speed, then it is not set up for cruise control. The point is that sometimes, 2bbl and 4bbl linkages are in a bit of a different location, and you might have to change your linkage so that it is not in a bind and has free travel. You can go the adapter plate route, but the problem there is that sometimes the accelerator linkage on the carburetor can bind if there is not enough clearance. Or it doesn't let the carburetor open up all the way. And if it does, the design of the adaptor plate does not let the fuel into the engine properly. There is the possibility of pooling of fuel on the intake manifold underneath the carburetor and when that fuel gets into the engine, it can cause plugs to eventually foul due to the excess fuel in the cylinders. I'm not saying that this WILL happen, but it certainly can. If it were my truck and I wanted to go to a 2bbl, I would go to a salvage yard and see if they had an old Chevrolet full size car from the early to mid '70s. Most of them came with the 2bbl setup. A number of Chevelles did too. Anyway, tell the guy that you are going to a 2bbl setup and need all of the stuff. If you buy it all the same time, he might let you have the stuff cheaper than if you go back a number of times for all the pieces. IF you were lucky, you might get a decent carburetor that did not need rebuilding, and might also luck into a good air filter in the air cleaner. That would be the big problem with used carburetors. They might need rebuilding. However, if you buy a rebuilt at your local O'Reilly store, there may be a "core charge". That is the term for the trade in. So if you did not have an old 2bbl to trade in, there might be an additional charge. One word of caution if you do get a used manifold: Chevrolet has a heat runner in the intake manifold that is designed to heat the carburetor in cold weather to keep it from freezing over. These ports are bad to stop up with carbon. Be sure to get that out so that the carburetor can function properly in cold weather. Am I correct in guessing you are wanting a 2bbl for better gas mileage? Sometimes that may help, but the problem there is that with the decrease in horsepower, the carburetor may be opened up to get the same power as the 4bbl, and thereby result in about the same mileage. And should it increase mileage, it probably won't be enough to offset the overall cost of changing to a 2bbl. Sometimes, what looks good on paper, or in our minds just don't work in real life. I know. Been there, done that more times than I care to admit. I wish you the best of luck in whatever you decide.

Answer 4

well the first thing is get a 2 barrell carb.and you can either change the intake and gasket or you can use an adapter,from a 4 barrell to a 2 barrell.

Answer 5

Not too difficult I did i once.. you need to get a correct 2 bbl intake manifold then a new 2 bbl carburetor. It would be easier to just put a good quadrajet on it and stay out of the 4 barrels. The small primaries on it will get you just as good gas mileage.

Answer 6

If it had a 4 brrl car on it
you will have to buy an adaptor plate for a 2 brrl

you will get better milage but not the power as fast as a 4 brrl

Answer 7

it will decrease horsepowers if you change to 2 barrels.you will be very upset when you found out that your truck barely move.to get the 2 barrels,just call pepboys and they will offer you a 2 barrels

Answer 8

If I'm not mistaken, the engines were designed and manufactured with a carb and cam shaft setup. If you try to change one without the other, you'll be causing yourself agravation.

Answer 9

you,ll need a intake manifold to put on it,,id go to a good junk yard to get one ,they wont charge much for one,but you,ll need a good carburetor for it, and a breather for it,and a gasket set for it,,there is no real cheap way to do this,,unless someone gives you a good carburetor and breather for it,,its going to cost either way you do it,,good,luck,i hope this help,s.

Answer 10

If you are thinking of doing this to improve mileage, you may well find that it doesn't change enough to make it worthwhile.