Can anyone recommend an after market intake manifold ( oval port) that will fit under the stock hood on a 454 (converted from a 350) 1973 Corvette? I'm sure a factory manifold will work, but I can only imagine how $$$$$$$ they must be! Thanks in advance.

Under the stock small block hood, well something like the Edelbrock Performer, but you will have to run a really thin air cleaner that if you have a Holley carb can cause problems because the bowl vents will be way to close the the air cleaner lid. In all honesty there are no good performance intakes that will fit under a flat corvette hood.

If I remember correctly, some guys are using Torker II's. Search corvetteforum.com and you'll find lots of info.

Another option would be a 68 or 69 390 horse alum. intake. It'll go under the hood and they're not tremendously expensive. Only down side is they're shaped for a quadrajet.

The sunken iron Q-jets fit and are pretty common. I would consider some sort of a hood bubble or something the sunken manifolds are real power killers.

I can measure the hood clearance on the very car in question if you like. My teacher at school just picked up a 73 big block Vette, numbers matching, unrestored. I'll upload some pics of it that I took after I trailered it home.
http://img.photobucket.com/albums/v249/BlueSS454/73%20Vette/P2270409.jpg
http://img.photobucket.com/albums/v249/BlueSS454/73%20Vette/P2270418.jpg
http://img.photobucket.com/albums/v249/BlueSS454/73%20Vette/P2270410.jpg
http://img.photobucket.com/albums/v249/BlueSS454/73%20Vette/P2270394.jpg
http://img.photobucket.com/albums/v249/BlueSS454/73%20Vette/P2270399.jpg

I've got a stock 73 454 intake manifold.
You want it ?

Nate, I'm pretty sure that the intake manifold needs to be the "sunken" type. I think those are Corvette specific, I may be mistaken about that. If all BB q-jet manifolds are the same, I have a couple available to me in a friends garage. Thanks for the offer!

same same !!!