Leaf spring brackets

Commando66 said
The size difference in the front spring eye bolt size is not a year to year difference. It is different from slant 6 cars ( 1/2" ) and V8 cars ( 5/8"). Firm Feel and Mancini sell stock height or 1" lower front brackets as well.

It is a year to year thing.

70+ have a 1/2" bolt. The 67-69 cars I've torn apart had 5/8", even the /6 cars were 5/8".

All my 70-72 340 cars have 1/2" bolts, including the 4 speed cars.