rochester/carter 2bbl carb bolt patterns

[Rapid Robert]

are the base bolt patterns the same or different? thank you for your time. RR

 

[RustyRatRod]

WHICH Carter and WHICH Rochester? There are more than one of each. The 2 main Rochester two barrel bolt patterns that everyone calls the small (3 1/4" x 1 7/8") and large (3 1/4" x 2"). Those are the 2G and 2GC respectively, I believe. I just went out and measured the bolt pattern on my Carter BBD and it does appear to match the smaller 3 1/4" x 1 7/8" of the smaller Rochester.

 

[Rapid Robert]

bro that helps greatly, I didn't know there was more than one on the rochesters. I will measure what I have so far.

 

[RustyRatRod]

bro that helps greatly, I didn't know there was more than one on the rochesters. I will measure what I have so far.

Yes sir. In fact, Trans Dapt makes an adapter that will go from the small to the large Rochester two barrel if yall are allowed an adapter. That bigger Rochester flows over 300CFM.

 

[Rapid Robert]

excellent, in this restricted (2bbl rochester) class 300 cfm will help me greatly

 

[408 swinger]

The two barrel restricted classes here run the big Rochester 2.

 

[Rapid Robert]

I'm pretty sure I have one or two of the big ones

 

[teringer]

just because it has a larger bolt pattern dosen't mean its much bigger, the large bolt pattern come in 4 or 5 different sizes from 275 up to 500 cfm the larger carbs were from the 350 to 400 cubic inch but only in the mid 60 to about 75 ,the larger carb is the same size as a 2-barrel holly with 1 11/16 throttle plate with 1 3/8 venturi. I due have a cast 69 318 2-barrel single plane intake that has the 1 11/16 carb opening I used on a dirt 360 with a 500 gm carb that I made. the holly carb for a 400cube mopar is smaller also have a 600 cfm gm but the track inspectors dont like it.