From what I've learned over the years, any 57 chevy passenger car could have been ordered with either the 270 horse fuel injected engine or the 283 horse fuel injected engine with solid lifters. I have seen 2 150 sedans with correct date codded 270 horse fuel injected engines.
The race prepped SEDCO cars had a larger fuel tank with four straps, six lug wheels, and the 283 horse engine.
The fuel injected cars where later banned by nascar and they were all converted to dual four's.
I have a 150 I've been building for a while, and cant wait to actually get the kit.