21xx Autolite/Motorcraft carb upgrade
Introduction The 1980 through 1988 AMC cars and trucks with the 258 engine came with the Carter BBD 2v carb. Two versions of this carb were made for six cylinder engines, feedback(computer controlled)and non feedback. The performance of this carb can be described as lackluster at best! The most common upgrade is to the Autolite/Motorcraft 2100 series(incl 2150). We'll cover a step by step upgrade in this section but before we start I'll give a brief comparison between the two carbs including what to look for in your new carb.
Carter BBD 6 cylinder feedback/non feedback 280 cfm
Autolite/Motocraft 2100 Measuring the base butterfly opening .98 = 190 1.01 = 240 1.02 = 245 1.08 = 287 1.14 = 300 1.21 = 351 1.23 = 356 1.33 = 424
The most common 2100/2150 in the junk yards is the 1.21, used on 302 through 390 v8 engines including 360s in the wagoneer to the end of the run in 92(actually 91). Some 2100 swaps may be considered failures due to drivability issues. Mainly because of over carbbing some of the drivability issues with the BBD will show up in the 2100, keep in mind bigger is not always better ESPECIALLY in a relatively stock engine. When choosing a carb be sure to get one that has the brake booster port on the rear. Older versions for cars AND trucks may not have it.