What kind of brake calipers on my ‘71 Duster 340?

A word of caution regarding the lug bolt patterns. When we converted the manual brakes on my 71 Duster to power disc we learned there were 2 different lug patterns dependent on the original engine installed. The slant 6 and 318 had the smaller 5X4 pattern while the 340 had the larger 5X4.5 pattern. As long as you have an original 340 you should have the larger lug pattern all around which will work okay when installing a new conversion kit. If you do have the smaller lug pattern you will have to find axles with the correct lug pattern or do as I did and replace the entire rear end. We did find during the process that SUMMIT could build the axles I needed but would not do so because they could not guarantee them.