are sb 427's really 427 c.i.'s

[Streetwize]

To compare what you can build either motor at 427", a stroker smallblock wins hands-down.

2 words....Modern Technology.

Take a motorsports block and put on a set of CNC'ed CHI heads and at 427", there's no way an FE can even come close in terms of horsepower. The last few EngineMasters motors have been small blocks with CHI heads that can flow close to 400cfm or enough for 800hp.

You have to compare Apples, cube for cube, aluminum block/head to the same. On paper and with a lot of $$$ you can build an all-aluminum FE that can make awesome power but at 427 cubes it won't make the power or torque of a 427 Smallblock with an 1800G bobweight. Since NASCAR went to 358" in the mid 70's the vast majority of high dollar technology was applied to improving the small block platforms of the big 3. And once the 5.0 hit the streets in the 1980's it became the 55 chevy of this generation and small block technology for very stout street use grew leaps and bounds while the 352-428 FE platform was (sad to say) ignored. The other reason the FE was not furrther developed was the packaging, 428's in mid-late 60's Mustangs were tightly packages and VERY NOSE HEAVY....once the boss 351 hit the street it became to motor of choice and today the Cleveland/Windsor hybrid with race blocks capable of supporting over 470 cubes are now the normally aspirated powerplant of choice.

The FE is great for the purist approach and I admire the ones that build a true replica that honor the originals; but the in line/narrow angle wedge head and horizontal runner angles just can't compete with a canted valve, raidsed port NASCAR Technology modern head in terms of breathing, and breathing means more power and RPM potential. But fact of business...the Cobras that actually won FIA championship and Daytona were all small block powered and the better overall weight distribution and better cooler running packaging make it a slam dunk in terms of Volumetric efficiency and a broader powerband. By the time the 427 S/C came out is was really obsolete because the racing technology and aerodynamics had advanced and the chassis though significantly reinforced over the 289 still suffered from torque flex.

I love FE's, I've been working on them for over 30 years but in a bang for the buck type evaluation, they just don't compare anymore. Just like a Harley, they still have a mystique, but not really the perfomance numbers to still compete head to head because modern technology driven by marketing/packaging/Performance Acceptance caught up.