the original came off a 4.3 liter in a 1980 and it was a two barrel. the replacement engine is a 350 with a 4 bbl. the casting no. on the intake is 22528212 it is aluminum and the thermovacume switchs are different. i have a picture of the original and a picture of the manifold that is on there now as soon as i figure out how to download it on this thread i will attempt to upload it.