[72 blackbird]

I say go for it- the SD 455 is far stronger than the production 455 and even the 400. But you will need to get the SD heads ported to make them compete w/ the latest aftermarket aluminum head offerings. It will cost quite a bit of money to drop this motor into a 3rd gen, but if you want to make it a low cost drop-in deal start w/ a 2nd gen Bird and put the money into the motor to get it into the 500-550 hp range, since you're not gonna get this level of power from a stock 455 SD.

Geno