heavy duty leaf spring confusion

[christianlarsen]

I'm looking at heavy duty leaf springs for 69 charger with 440 and automatic transmission.
classic has item ML217 and summit P4452982 (passenger side example).
they both have 7 leaf and look the same, but summit states they are for manual transmission (when used on 1967-71 b-bodies) and classic doesn't mention anything about transmission. There is a huge difference in price (classic 350 and summit 170) and i wonder why. Can anybody enlighten me and help me decide?

here are links to both:
https://www.classicindustries.com/product/1971/dodge/charger/parts/ML217.html
https://www.summitracing.com/parts/dcc-p4452982

[b5blue]

Call Mancini Racing.