Hood Shakes At High Speeds
 

Just got back from the Hot Rod Power Tour, did the last leg and put about 1,200 miles on the girl.

Anyways I noticed a good amount of hood shake on the highway, speeds between 70-85.

Turbulence from semis and vans would make it a lot worse.

I pulled over a few times, adjusted the latch and bumps.

If I get it all lined up like butter it shakes like hell at high speeds. If I drop the latch and raise the bumps, the alignment is a little off but not near as much shake in it.

Ahh, just frustrating. Got me thinking about tossing some hood pins on it.

Anyone else notice any shaky shaky?

When the hood is latched can you rattle it a little if you hold on the front sides of the hood & shake them up & down. Sounds like you don't have enough tension between the hood latch & the adjustable bumpers the hood rests on. I suspect the front corners of the hood need to be drawn down tighter on the bumpers/spacers. Maybe they are out of adjustment & the bumpers need to be replaced. When the hood is latched it should feel rock solid & it should take a little effort to unlock the hood latch. I may If you can't get it, take it by a body shop & they can likely adjust it or tell you what's wrong. I may be all wet as I'm just going on building a lot of old Chevies!

Same problem on mine. As Mr. D said adjust the rubber stoppers. Turn the front two out half a turn at a time until it goes away, or drastically reduces. Worked like a charm on mine.

Yep definitely helps but not a cure all.

I still get a shake at high speeds, 70+ with the bumps tight and hood aligned properly.

Normal around town driving won't do it, only at high speeds on the highway in turbulence.

Like I said before, I can lower the latch and turn the bumps up, the shake will go away, almost completely at very high speeds, but alignment of the hood is off.

I may toss the heat extractor vents on it and see if the added air flow helps.

This has been a problem since 05. There isn't anyway to eliminate it, you can adjust the stops, add a hoodscoop, or hoodpins to control it but it will always be there to some degree.

It has to do with the thinness of the aluminum.

installed hood shocks,helps support hood sides,100 bucks and looks cool

This is the correct answer.^^^^^^^^

Hood shake fix
 

I found cutting out the honeycomb vents in the hood let's out maybe 20-30 percent more engine compartment air. Now high speeds,winds and semi passing has minimal hood shake...was violent before.

Unless OP's hood is actually misaligned, it was never an actual "problem" rather than a perception. I don't know about pre-99 but the new edges also had a composite hood that wobbled at freeway speeds.
A professor I had in college had a story about that exact thing when he worked on a carbon fiber station wagon for ford in the 80's; the marketing and focus groupd people couldn't get over things like hood wobble and doors that felt less "sturdy" even though it was just as safe and had superior performance and mileage than the steel bodied equivalent. People still think cars from the 60's are safer than modern cars for the same false reasons.

Hood struts reportedly help a lot and get rid of using the basic rod to hold the hood up.