The photo below was posted in a recent ebay auction, with the following description:
The two LHS ones are for a 428CJ, the third one is the 68 GT390 - they're very similar but different - the final tube is for a 390/352/360 PCV setup as defined by the angle of the nipple on the tube to acount for the difference in intake manifold height between the engines in question.
Is that an accurate statement? Are there tubes with different nominal angles? Or is there one design with a fair amount of variation at assembly?