I finally picked up my first Corvette: a '79 that looks great on the outside, but the previous owner should be jailed for neglect. There's plenty to be done under the hood.

Question 1: If I replace the engine and transmission with a modern 350 crate engine and trans, will I still need to keep the '70s smog equipment on board or could all those hoses be eliminated? What if I go with a modern LS2 and a nice 5-speed auto trans, does that make a difference regarding smog equipment?

Some insight before I open my checkbook is appreciated!  

On the smog equipment, it all depends on what state you live in. in the people's republic of California, you'd have to keep all the smog stuff.

Here in Florida, you could just rip it all off, no problems.

Where do you live?  

Yes. I do live in Southern California. I heard that the regulation here is that the vehicle has to be 30 years old before it is smog exempt. So, I am hoping I just have to wait a year before I replace the engine and transmission with something without the required smog pump. Any suggestions?  

I'm in the same boat, only in No.Cal. The Govenator froze the smog exemption @ 1977 vehicles and earlier. Is there anyone out there who has experience with the California smog requirements that can make recommendations on how to upgrade / replace the powerplants in late 70's early 80's Corvettes and still pass smog. Pensive in San Jose.  

That's the lunacy of the California emissions laws. You have to use the factory smog equipment for your vehicle. So basically you have to have your AIR pump and have it pulling form the exhaust and feeding into the carb. There are headers out there that have provisions for these plugs.

One thing that'll help your motor pass smog, make sure you've got a storng enough ignition system that'll burn off any excess hydrocarbons, and that your carb/FI system is tuned just right for air fuel ratio so it's not running rich.

On changing the motors, here you have to be creative and sneaky. It's obviosuly easier if you use a crate motor with iron heads, the smog guys will never know the difference. If you have aluminum, you might have to paint the heads so they look like iron ones.

Really the laws shoudl eb set up that your car has to run equal to or better than the required emissions numbers for that year, unless exempt from emissions testing by law. That way you can put modern parts in your car, and as long as it burns clean, who cares if you have/don't have the AIR pump.  

Question 2: Will most NEW crate motors accept the original headers and smog equipment?  

As long as it's a standard Gen I SBC, everything should bolt up fine.  If you swap to an Gen II or Gen III motor, or big-block, then you'll definitely run into some issues with bolt-ons.  Keep in mind that if you wish to swap to a Gen II or an LSx motor, as long as you swap with the proper exhaust/catalytic(s) to meet factory spec from a newer gen 'vette, you should easily meet emissions standards.  Which brings me to the next option.

Something you might want to look into, regardless of engine, is replacing your catalytic with a newer dual cat setup.  More than likely, even with keeping the smog pump installed, the car may fail emissions out of the pipe because the cat is so old.  Get a dual cat setup and you can have a true dual exhaust and meet the emissions requirements.  Hooker has some good headers with smog pump provisions, if you wish to remain close to factory spec, so you can still put together a good performance exhaust system and stay legal.  And using new cats could eliminate the need for the smog pump if it can pass the sniffer without it.  And you're also more likely to pass the sniffer with a computer controlled fuel-injection system than a carb.

Basically what it comes down to is how much you're willing to pay.  There's plenty of options out there that can keep you legal, though some may be questionable at best.  Study the law, use your best judgement, and if you have questions, ask the people who will be performing the test.