My writing from Erica at Harley-Davidson Motor Company report to me.
Having been in contact with the Motor Company through the contacts I have made over decades and enquired about the TSB 1450 events I have been assured by them that. 1 They have never warrantied any customer for multiple engines consecutively though some were changed for other reasons not specified..2 There has been no Softails ever warrantied for a TSB 1450 event.Their figures for a TSB 1450 event are less than a quarter of one percent (.25%) No TSB 1450 event warranty has ever been given to a customer with aftermarket parts in the engine. That shows me with this latest communication and my own experience the event is rare.I have been informed that the Motor Company will be taking an active role in the future to prosecute fraudulent behaviour by using internet forums to track individuals doing so.So the early build M8's had a 1 in 400 chance of a TSB 1450 event , a much lower failure rate than the Twin Cams .

So I remember .

n the 4.375 stroke 107 engine the 4.180 bore would take it to 120”

Lot's of possible combinations to build engines but HD only offers three from OEM
107 which is really 106.5464 or 4.375 x 100mm bore @10.0:1
114 which is really 114.018 or 4.500 x 102 mm bore @10.5:1
117 which is really 117.378 or 4.500 x 4.075 bore @ 10.2:1

Then there is the SE Big Bore upgrade kit that offer a 4.075 bore cylinder and piston for each of the OE sizes

107 to 114 which is really 114.117 or 4.375 x 4.075 bore @ 11.0: 1
114 to 117 which is really 117.378 or 4.500 x 4.075 bore @ 11.0: 1