I bought a Glasstek W-25 style hood for my 69 442. I also bought two new hinges from Summit Racing. I thought finding suitable hood springs would be a snap. I was wrong. I bought three different sets from three different vendors with no luck (I suspect these springs are all made in the same place). So, I copied a trick that was done on Quadrajet throttles for decades, the old double spring. McMaster Carr was my go to for these "helper" springs (I used part number 5667N324). The Hood now stays in place when it's up. 

 

I used factory 66 chevelle hood springs on the last repop fiberglass hood I installed. Worked perfectly. The problem is that even in all fiberglass, these bolt on hoods are still pretty heavy.

 

Make sure it's not TOO much spring to overcome when closing, or you could put undo stress on the hood at the front of the hinge and eventually crack it. It's a careful balance.

I swear, I've removed and installed hoods by myself and I swear the OEM W-25 hoods are heavier than the regular steel hoods. I would imagine a full fiberglass hood wasn't that much lighter than an OEM.