Rochesters definitely have advantages over the old Stromberg’s. One of the biggest problems on the Strombergs was using too much fuel pressure, they can only take 2 ½ - 3 PSI without blowing thru the needle and seat.

After looking at the prices for people are asking for 2G Rochesters (especially outboard carbs) I’m not sure you will be saving much over the Strombergs. There may be some cheaper options with the Rochesters however. Often times rebuildable units can be found for a few bucks at swap meets etc. They’re a simple carb to rebuild and even modify for outboard use.

I’ve played with Rochester Tri-Powers since the 70s, you may already know all this stuff, but just in case:

The first thing I’d look at is the carb spacing on the manifold to make sure the Rochesters will physically fit. The Dodge motor is shorter than their Fire Power cousins so that might be an issue.

The Rochesters 2 Gs come in 2 basic flavors, the small base and the large base. You will want the small base version based on you engine displacement (and it’s what the adapters are set up for).

This is the Tri-Power I built and ran on my 354 Hemi for several years. It’s set up with a large base 2G center carb and small base outboard carbs. If you look closely you can tell the center carb (the large base) is physically larger than the outboard carbs. The intake is set up with progressive linkage and the larger center carb is the one the engine runs on the majority of the time. The larger carb was used on this car to improve drivability when only running on the center carb. The linkage is set up so that the outboard carbs don’t open till about 80 MPH when cruising on level ground.


T2 by M Patterson, on Flickr

Generally speaking the majority of small base carbs have the fuel inlets on the side (although there were a few made with front inlets) and the large base units feed from the front. The large base unit shown here has had the original inlet capped and was drill and tapped on the side of the filter housing for a new inlet. I normally don’t run filters in the carburetors, but rather rely on a good in-line filter.

If you go with Rochesters I would recommend 3 small base carbs with side inlets and progressive linkage. If you use Strombergs you could probably get by using stock units with synchronized linkage due to the small CFM of the Strombergs.

T1 by M Patterson, on Flickr

On true Rochester Tri-Power outboard carbs there are no idle or transition circuits nor are there any idle adjustment screws. There is also normally no power enrichment circuit or valve. The lack of idle and transition circuits make it much easier to get a good idle out of the engine (idle adjustments are all handled with the center carb). The idle and transition circuits are in the base plate of the carburetor. Back when I started playing with Tri-Power setups factory outboard carbs were almost impossible to find so I ended up modifying base plates from standard 2G carbs myself. I modify the base plates by soldering the idle and transition passages and idle adjustment screw hole closed. I generally leave the stock power valve operational. The last step is to insure the throttle plates completely close. From the factory many of the throttle plates are not properly centered in the bore. This is solved by loosening the throttle plate screw and centering the plates. On a side note, some of the small base Rochester 2G carbs stopped using screws and went to rivets to secure the plates to the throttle shaft…..I usually stay away from those.

If you want to avoid the hassle of messing with the base plates they still sell outboard 2G base plates separately.

One of the down sides of the Rochester 2Gs is the lack of jets available for them. My experience is that the majority of them came with 48s in them and that actually seems to be a good all around size (although you might want to try 46s if you can find them). I’ve taken this car from 4500 feet where I live to 200 feet back in Illinois and the jetting seems about right…….although I do usually retard the timing a bit when I get back to Illinois.

As far as air filters based on your engine size you can probably get by with the round 4 5/8” units that are popular. I’ve personally found on anything above 325 CI, those air filters seem to choke the engine (with progressive linkage that filter has to handle all the air going to the engine until the outboard carbs open. Years ago I found larger air cleaners for VW powered sand rails. You had a choice of a centered or offset base so I picked some up. They fit well on this setup.


AC 1 by M Patterson, on Flickr

Although my normal go to air cleaner are the repop Ford dual quad/tri-power units.

T3 by M Patterson, on Flickr

One last thought on running a Rochester setup with progressive linkage and the bases without idle circuits. You will have to nail the throttle every once in a while (never been a problem for me LOL). Especially with the crap gas we currently get the gas in the outboard carburetors can get stale and varnish up……opening the end carbs once in a while will ensure they are filled with fresh gas.