Recently purchased a 67 Chevelle and it has a fiberglass cowl induction hood (2"). The springs do not hold the hood up. Does it require different springs - or will replacing them with
original '67 hood springs work? It's been a real pain trying to work under the hood.

When I bought the glass hood for mine I also bought lighter springs to go with it. Stock springs were too stiff. If yours aren't holding the hood up you may want to get another pair, but I wouldn't suggest getting stock springs.

My understanding is that if you use stock springs with a glass hood, you will crack the fiberglass because the springs are to stiff. I used the light weight springs with my glass hood, it stays up just fine unless the car is running, then it slowly comes down. To cure this, I drilled a hole through the center of the hinge, and I install a hitch pin when I want it to stay up.

Glasstek fiberglass parts in Illinois have the springs that you probably need: glasstek.com or (630)978-9897, I've had one of thier 3" cowl hoods with their light weight springs since 1998 still running with no problems, also I'm not so sure that the springs they use aren't GM pieces because we've got an 1980 Pontiac Catalina and the hood hinge springs look like they would certainly pass for my Glasstek springs but I'm not 100% sure. I hope this helps and sparks some ideas. Thanks