It seems like we talk about block weight a couple times a year here.
For the record:
OEM 427 side oiler block = 195 lbs
Pond alloy block = 135 lbs
Shelby alloy block = 125 lbs
(
Shelby 427 FE Bare Block | Call Us @ 707-836-1534 | Carroll Shelby Engine Company)
10 lbs is 10 lbs.
And the cast iron BBM block is 250 lbs.
So, now the difference between a Shelby alloy block and the BBM cast iron block is 125 lbs. Of course, if they actually do make them and you can get one sometime before the sun burns out or does a supernova.
BBM Cast Iron FE Engine Block (FE427 Side Oiler) | Bear Block Motors