Sounds like another screw up. Allowing the parts to be used to keep other clunkers on the road is counter productive to the purpose.
Hey now, If I can find a low mileage 4.3 V6 for my 1999 S10 4x4, By all means I'll pick it up for next to nothing! Granted It's a 1999 with 300,000 miles on it, It's still rides and runs like a brand new truck. I'd like to take advantage of the program, But my truck gets 18-20 MPG average and I don't think a new Chevy Colorado Z71 qualifies in the program......