View Full Version : Rochester Carb Inquiry for 3 X 2 Set Up


51ChevPU
03-20-2008, 12:11 PM
I would like to run some old Rochester 2 bbl carbs on a 3 x 2 set-up for a small block chevy. I have no clue what type of two barrel carbs I should be looking for. What years of vehicles were they on and so forth. If anyone is familiar with these carbs, maybe they could post a pic and give me some guidance on what I should be looking for at the salvage yard. Your comments and guidance will be appreciated. Thanks.

Tman
03-20-2008, 02:03 PM
60s GM pickups You want 2gs

Mopar34
03-20-2008, 02:17 PM
Rochester 2G's. You can usually find them at larger swap meets, even might find an intake to go with them. Rebuild kits are available. Places like HotRod Carburetion sell them completely rebuilt but they are pricey. Better to get nice used ones and re-do.

I know where there are three in very good condition that you can get for about $20K. Kind of steep, but you get a real nice 57 Olds J2 mild kustom to go with them.:eek::D:D:cool:

Jimv
03-20-2008, 06:11 PM
Make sure the fuel inlets are on the sides, not in the front!! Rebuild kits are cheap & availible everywhere
JimV

sho1off
03-20-2008, 07:16 PM
if you cant find the numbers try this http://www.guaranteedcarbs.com/ I was having a hard time finding a Rochester for my boat and they had it reasonable price and fast shipping

beetlejuice55
03-20-2008, 09:15 PM
fuel inlets in the front makes it harder to get all 3 fuel lines on. i suppose you could make them work with some 90 degree elbow fittings but the desireable 3 deuce carbs will have the fuel inlets on the sides.
all factory equipped tri-power setups used the carbs with the inlets on the sides.

pecker head
03-20-2008, 09:30 PM
What's wrong with the fuel inlets on the fronts? I'm asking because thats what I have. I was told they're an original late 50s tri-power set up.
I have fronties also !

Redneck Smooth
03-20-2008, 09:52 PM
They look like this minus the hot rod air cleaners. Most late-50s GMs had em. You want the small-base carbs for a multi-carb setup, or so I'm told. Grab one off a 70s truck to see the difference between the newer large base ones and the older small-base ones. Oreilly sells a rebuild kit for $12 and they're usually in stock. Do NOT buy a NOS rebuild kit from the dude on eBay and actually expect to use it, the old-as-hell plunger for the accelerator pump will disintegrate in the pump well and leave you with a weird lean spot right off idle. Oreilly's includes the nice new accelerator pump. Don't bother to buy the rebuilt ones either, rebuild it yourself, it's super-easy and then if it breaks, you'll be able to fix it. Here's mine ready to drop on our '58 Olds....

http://i101.photobucket.com/albums/m58/timhypo/DSCF0898.jpg

draggin'GTO
03-20-2008, 10:08 PM
fuel inlets in the front makes it harder to get all 3 fuel lines on. i suppose you could make them work with some 90 degree elbow fittings but the desireable 3 deuce carbs will have the fuel inlets on the sides.
all factory equipped tri-power setups used the carbs with the inlets on the sides.On this '66 Pontiac Tri-Power (factory original carbs and fuel lines) the center carb is a front inlet, only the end carbs are side inlet.

Note the elbow on the center carb.

All 3 carbs are the large-base Rochesters, '66 was the only year they were made this way. From '59-on the outers were large-base, the centers were small-base. The '57 -'58 setups were all 3 small-base carbs.

http://i137.photobucket.com/albums/q230/b-man64/1964%20Tempest/DSC00847-1.jpg

rocket hot rod
03-20-2008, 10:23 PM
Nothing wrong with front inlet carbs, but one thing to watch for on the front inlet carb cover is a cracked inlet. Overtightening, or overtightening while trying to position the 90 degree fuel line fitting just right contributes to this. I've had two of them.

Jimv
03-21-2008, 08:32 AM
i had front ones at first & used 90o els on them I had to trim them alittle to fit them.The chevy 3x2 is tight. even the dist. is close.
jimV

willowbilly3
03-21-2008, 08:47 AM
So what do you have to do to original single carbs to make them work on the ends? The obvious is remove the butterflys and somehow disable the idle circuit. What about the jetting and power valve? What is the best way to disable the idle circuit? Just crank the screws in?

northerndave
03-21-2008, 09:21 AM
speedway sells bases for the rochester 2GC carbs for tri power set up.

primairy (center carb) will of course still use choke plate & idle mixture screw type base but your secondary/outbourd carbs will have a base with no idle ciruits or screws. Check out speedway, you'll find it there. next prob will be the linkage... but they have that as well :grin:

good luck!! I've wanted that setup myself ever since I was a kid. Got a 327 in a 66 chev 2DR caprice I'd like to strap a tri power to.

northerndave
03-21-2008, 09:26 AM
check it out holmes:

http://www.speedwaymotors.com/p/5963,391_Rochester-TriPower-Base-Kit-with-Linkage.html

Redneck Smooth
03-21-2008, 09:27 AM
That's interesting, those look like front fuel inlet carbs. Got a pic from the other side? Are they original Olds tri-power carbs?

Here's a pic of mine:


I never really thought about it, but they are. I was told they were original to the J-2 from a '58 Olds and the two outer carbs don't have any idle circuits and the other crap that indicate they were originally from a tripower setup...

trad27
04-23-2011, 10:16 PM
Everyone says try search and I did and couldnt find it so I will try bumping this one before starting my own. does anyone have dementions of the small and large bases or a quick way to ID them? Also if it is a large base and I buy the speedway kit that comes with the outer bases with those bolt up so I can use the carb body? thanks in advance.

carcrazyjohn
04-23-2011, 10:23 PM
Ive got one in the classified ,Needs a rebuild ,but good core.Side inlet ,307 chevelles had them........

dickster27
04-23-2011, 10:52 PM
fuel inlets in the front makes it harder to get all 3 fuel lines on. i suppose you could make them work with some 90 degree elbow fittings but the desireable 3 deuce carbs will have the fuel inlets on the sides.
all factory equipped tri-power setups used the carbs with the inlets on the sides.

Sorry Buckaroo, Olds and Cadillac had side inlet 2G's. And they are just like the side entry other than the absence of the ability to use an internal filter.

Any 2G from '55 thru '68 are good carbs to use for your tri power. You can still find good cores for $35-$45. You can also still find real tri power carbs but they are rather salty.

tommy
04-24-2011, 08:42 AM
Everyone says try search and I did and couldnt find it so I will try bumping this one before starting my own. does anyone have dementions of the small and large bases or a quick way to ID them? Also if it is a large base and I buy the speedway kit that comes with the outer bases with those bolt up so I can use the carb body? thanks in advance.
http://www.fototime.com/%7B67BFC369-14F2-4DCE-8FD0-A4DE40229035%7D/origpict/rochester%2520base.JPG

I always turn them over and look at the bottom. I look at the exhaust gas passage. Once you study it and notice how 2 of the carb bolts go through that passage, you can identify one in a second. The 3 deuce conversion parts to make end carbs are all sold for carbs with this base....extended shafts and thick butterflies etc. etc.

53 hemi
04-24-2011, 09:27 AM
Junkyards are always a good idea, but to put it in perspective I bought two rebuilt ones from advance auto parts online for under $300 total. I used a 62 Biscayne for the search. They are side fuel inlets. Not a good photo, but they have been good carbs. I did have to buy new accelerator pumps. http://www.jalopyjournal.com/jal_mu/a6890c9d-3402-c799.jpg

trad27
04-24-2011, 10:46 AM
I always turn them over and look at the bottom. I look at the exhaust gas passage. Once you study it and notice how 2 of the carb bolts go through that passage, you can identify one in a second. The 3 deuce conversion parts to make end carbs are all sold for carbs with this base....extended shafts and thick butterflies etc. etc.


Thanks, just the info just what I was looking for. So the small and large bases dont interchange with the carb bodies? well looks like I got the wrong one, anyone need a large base core for thier project?

vtwhead
04-24-2011, 11:05 AM
all factory equipped tri-power setups used the carbs with the inlets on the sides.[/QUOTE]

'58 Chev 348 came with front inlets FWIW:)

draggin'GTO
04-24-2011, 11:12 AM
Here's a shot of 3 genuine 1964 Pontiac Tri-Power carbs mounted on a 1965 intake. The center carb has the inlet in the front and end carbs both have side inlets.

The factory Tri-Power carbs were not all side inlet carbs.

http://i137.photobucket.com/albums/q230/b-man64/1964%20Lemans%20Convertible/1964%20Tri-Power/GaryForemansTripower006.jpg

carbking
04-24-2011, 06:51 PM
Factory tripower using front inlet Rochesters:

Cadillac:

1958 - all
1959-61 center

Chevrolet:

1958 - all

Oldsmobile:

1957 - all
1958 - all
1966 - center

Pontiac:

1957 - all
1958 - all
1959-66 - all centers

Jon.

1oldtimer
04-24-2011, 08:01 PM
What's wrong with the fuel inlets on the fronts? I'm asking because thats what I have. I was told they're an original late 50s tri-power set up.

if you have the ones with the small hole (NO inside filter) then they're ok. the front feeds you don't want are the 70's V-8 ones (unless you have enough motor for them), they're the large base 2 jet with a filter inside that takes a 1" wrench to get off.

you want small V-8 from the 60's and older. side feeds are easiest to spot.