I have a Repro in front of me and a Original off of a 1970 Chevelle.
The two together really show the following differences.
1) Original early has either a smooth bottom or later a channeled bottom base.Repro has the channeled as well,but is less defined.
2) Original has a metal tube almost at a 90 degree angle on the bottom for the Crank case hose to attach.Repro has this tube,but at a sloping angle,no corners in it at all.
3) Repro has the letters C H Q stamped into bottom base where snorkel is.Original does not.
4) Originals snorkel has a Small 1/2" gap in the side seam of it.Repro has this seam,but no gap at all,it is a straight line.
5) Where the Originals snorkel meets the housing,it has a very pronounced bulging crimp on both sides.The Repro has a very smooth crimp.Almost tapered.
6) When you look at the underneath of the Original,it has wrinkles in the metal where ever it curves up and around.The Repro is all continously smooth in these areas.
7) Even the Dented area where your Distributor sits is Full of ripple lines on the Original.The Repro shows very few of these lines.
This is what I have found.There maybe more differences as well.Prices on E-bay reflect that some wll pay more for these differences.
There is also two different designs for the Cowl Induction hood.But that is another topic.
1970...ON THE MOVE
[This message has been edited by mr70 (edited 07-08-2001).]