A Body front suspension clarification

[dustyfool]

I am confused about the difference between pre '72 and '73 on, front suspension. I understand larger ball joints were incorporated and 4 1/2 inch bolt pattern was used in A-bodys beginning in1973. My question is, was this upgrade only in disc brake cars or in V-8 cars? I have a '73 Duster that was originally a slant 6, drum brake car in which I have installed a 360. The ball joints and wheel bolt pattern look kinda small. Does this car have the heavier parts or do I have to swap in front end parts from a V-8, disc brake A-body?
Thank you for any help you can give me to remove my ignorance.

 

[JLP]

The upgrade was for all disk brake cars not just the V8's. Your car being drum brakes should be small bolt pattern. So you need the upper control arms, spindle and brake components from a 73+ disk brake A body. You will probably also want to change the rearend out to big bolt pattern, also would recommend a 8 1/4 or 8 3/4 for the 360, the 7 1/4 will not last long if you race it.

 

[tobysoldblue]

they went to upper ball joints larger in 73,but im sure thats not the rule for all 73 up cars,because the factory used up what was left on there shelves.The k frame changed too,of course,to spool mount type.

 

[73NorthernDuste]

My 73 Duster with a six had small bolt pattern drums up front but for 73 the upper control arms got the big ball joint. So if you want to convert to disc you need new spindles (I used f body ones) new lower ball joints and a disc m/c and proportioning valve. www.bigblockdart.com has a good article on the swap.