This excerpt from the Shelby site indicates >1500 HP from his aluminum BB.
The address is:
http://www.carrollshelbyent.com/engi...inum_block.cfm
I hope this paste works, it didn't; so the above address will take you to the specs for the engine and, while there, you can find Shelby's explanation of why an updated aluminum block. It looks like it is back to the same place on this issue" point of view. Here is an MSW shot at it:
Shelby 427 Aluminum Block Technical
Features:Block material A356, T6 aluminumBlock is CNC machined
Deck height: 10.150-inch
Deck thickness: 0.750-inch
Cylinder bore range: 4.250-inch,
std., to special order 4.440-inch
Maximum stroke: 4.500-inch
Displacements: up to An easy 525 cubic inches
Cylinder sleeve: Centrifugally cast ductile iron
Cylinder wall: Siamese with dry liners
Main bearing cap: Billet Steel
Main bearing cap bolt configuration: Studs; 4 cross bolts on 2-3-4 mains
Oil sump: Accommodates wet or dry sump oiling systems
Head stud diameter: 0.500-inch
Bare block weight: 125 pounds, approximately
Horsepower range: 1500 plus
All the best gentlemen,