I have always been fond of the Motorcraft 2bbl carbs for off-road use, due to their ability to handle angles and bouncing. I am running an early-mid 70's stock 460 in my off-road rig. I used a 2 barrel adapter and a 2" spacer (the spacer was on the truck when I bought it) with good results. Several months ago, the carb starting acting up & I wanted to try a Quadrajet....heard they worked well off road, and would provide a definite power increase over the 2bbl. On the road, the Quadrajet definitely had more passing power, but low end response was not as strong....I expected this. Overall, I liked the off-road performance better with the old crusty 2bbl.

My truck is currently under-geared for some of the things I use it for (off road). I understand that. However, it had a lot more off-idle grunt with the old 2bbl. I wanted to find the largest 2bbl (venturi size) to use on the 460. Ford did not use 2bbl’s on any of their 460's that I am aware of. They did use it on some 429's. So, I assumed that the 429 would have the largest 2bbl: 1.33" venturi size. I ordered a remanufactured unit from Autozone the other day. I specified the vehicle as a 1969 Ford LTD with a 429 2 bbl. I picked it up today, and it is stamped 1.08 on the side? What gives? Could it have larger venturi’s in the carb housing? I know all of the carb housings are the same physical size.

I have used three different 2100/2150 units in the past:

1.08 from an ‘84 302 F-150 truck engine
1.21 from a ‘74 400 from an LTD
1.21 from a ‘78 351M Bronco

I was expecting the 429 to use the largest venturi's of all of the 2100's.

I am interested in what will give me the most off-idle grunt out of my 460. Would the 1.08 be superior, or the largest unit, the 1.33. I understand the 2bbl is giving up a lot of top end power, but I don’t care. Anything over 3000 rpm is of no concern at this point.

Can someone give me some insight on this?

Thanks,
Buford

Try a 1971 ltd with a 351M. that was the only year that they did not have the modified cut back for emissions. In 1972 the cut the compression and timing in the cams way back. It took almost a 100 HP from them. Hell its worth a try.