Chrysler starter spin down time

It's a Chrysler trademark for sure.
Those starters have an overrunning clutch on them, to deal with engaging them with engine running.It's not a big deal, unless you did it every time for like 10 years.
Chrysler made those old starters in several flavors, and they are interchangeable. Be sure to get the six banger one.I believe it is rpm limited, by internal wiring.

The spin-down time is related to how fast it is spinning when you back-off the key. A high compression engine, or a cold engine might be spinning at a slower rpm than a tired or hot, slanty. Or if you fail to release the key in a timely manner. These are all factors.

Even at the slight bump of the key mine will spin down for 4-5 seconds. I went on youtube and found some videos of others starting their cars and indeed some do stop almost instantly when the key is let off.

check out these videos [ame="https://www.youtube.com/watch?v=FPeH_RB9tjM"]Reduction gear starter on a 1st gen hemi - YouTube[/ame]

[ame="https://www.youtube.com/watch?v=TxV570Fs3PU"]20-degree Slant Six cold start - YouTube[/ame]

As far as getting a starter specifically for the six,I have always heard they are non-specific and can be interchanged among the lot,but there was never a specific starter for the slant six only. How can I identifity the "six banger" one?

heres a video showing the short and large frame starters,he claims they are all interchangeable,and the large frame didn't come out until 1975 for use on the bigger v8s to combat heat related hard start issues. until then he says that Chrysler used the same starter for the slants and V8's.
[ame="https://www.youtube.com/watch?v=NRuIHTWZHw0"]Identifying Chrysler gear-reduction starters - YouTube[/ame]

in this video he tests them and they all seem to stop in seconds.
[ame="https://www.youtube.com/watch?v=PKsZvTDHij8"]Chrysler starter comparison - YouTube[/ame]