Tomorrow I'm planning on mounting an A990 scoop on the hood of a '65 Coronet. I realize that I'll have to drill holes in the hood support to allow access to the mounting bolts.

I'm looking for some pointers from you guys.

What size holes have you drilled for the mounting bolts?

Any other techniques would also be welcome.

Thanks

Never mounted one of those types of hood scoops before, but I have done the fiberglass twin scoop type that came on 69 and 70 cars. Those have the benefit of having some of the location holes already punched in the bottom bracing to use as starting points.

You'll want to use a stepped drill bit or a knock out / chassis punch instead of a regular drill bit if the holes are largish. Normal drill bits on sheet metal tend to make octagons instead of circles.

Hole size? I would find out what the size of the original holes were from someone who knows if you can. Likely a little bigger than whatever sized socket needs to go in the hole in the frame support below.

Hole size for the air thru the hood openings? Hole saw bit turning really slow is fine. Should not need any cutting oil or anything on sheet metal.

Paper pattern taped to the hood with the holes marked out then centerpunch the holes and start drilling. For the ones that go thru the bracing I would use a small drill bit and go clean thru both parts and then flip the hood over and drill the larger holes from behind. If the hood is upside down vacuum the metal shavings out from drilling the large holes before you flip it back over otherwise some of it will inevitably get trapped in the bracing.

Is this a metal hood scoop? If so, I think the bolts are tiny, maybe 10-24 thread? There should be clips in the scoop that the bolts go into. On my Coronet most of the bolts go thru one layer of sheet metal. There are a couple of bolts that go thru the support. When they go thru the support you need a small hole in the skin of the hood and then a larger hole in the support so you can get a socket head in there.

It's a fiberglass scoop that uses J clips and 10-24 bolts with captive washers. On the original cars they cut away most of the inner bracing so there wasn't much of an issue with having holes to run the bolts through.

I'm not going to be cutting holes in the hood for the scoop to be functional.

Why not?

I'm going to drive the almighty hell out of this car. Before I sold my '65 Satellite, I put 8000 miles on it in 18 months and I plan on doing the same with this car. Actually putting a scoop on it makes no sense anyway since it will just "slow" me down a bit and increase my gas mileage. Don't forget the chance of some random damage.

I don't want the extra water and bugs and everything else that will be ingested into the engine compartment if I were to cut holes into the hood.

Make sense?

It's mounted, wasn't the worst thing.