It has been shown before on another link, but it doesn't diminish it's impact. Well done Gus.
I'll sling my carry bag over the ring land breakage. In Australia, early Ford Falcon sixes never progressed to the slotted ring lands, but Holden in line sixes did with the exception of the the 1971 to 1973 GTR 202/3300 XU1 Harry Firth redesign drilled hole oil relief ring lands, supplied by Mahle to Repco Australia, later ACL.
The pistons came from the West German Ford Cologne 1990 and 2555 60 degree V6 design, in high alumino-silicate content HyperEutectic alloy. The interim solution for others using the older stock OEM 173/186 and 202 cubic inch slotted design was to TIG weld the slotted oil relief, and then drill circumferential oil holes. That way, the ring lands never separate.
This info means you can then use the Silvolite 1189P piston, but you have to weld the slotted section under the oil relief. Or use the US made 200/250 1985 low tension thin ring Australian design slotted HyperEutectic...which doesn't have the ring land separation issue.
And another one of the many Turbo in line six Mustangs on the Youtube network
Cast pistons are a thing of the past
Turboroni Jabroni made 400hp and 500tq on a 1980 head built by Jeff Jones at Vintage Engine Works.
Fordsix.com has plenty of info
and there is a Facebook group dedicated to these sixes called vintage mustang 6 forum
1 hour video on the keystones