How can I go about raising my 1981 C3 Corvette to get more ground clearence?
Install a hydraulic suspension system, like the kids that “slam” their cars?
Find a good shop that does these conversions, bring them a big bag of cash, and they’ll be happy to do one for you.
Seriously, try vintage Corvette forums and/or magazines. There are countless ones out there. That’ll be your best source of ideas.
Install new stock springs…That should lift you up a little… Or install some custom made springs…For the rear, air-shocks will do the same thing…A wheel, frame and axle shop will have many options…
I really don’t need to slam my car because everytime I sit my big B _ tt in it, it slams. Thanks for the info as it gave me more options to look at and a place to start.
Never thought about the air shock trick. Between the springs and shocks I should get a substantial lift out of it. Thanks for the info.
I’m sorry…but I have to ask WHY??? Why would you want to do this a truly American Classic vehicle???
An '81 'vette is anything but “classic”…It’s a smog slug…
I can certainly understand wanting to raise a car. If the car isn’t up to specs, it may just have worn out springs. Otherwise, the car has to be practical to drive on pothole infested roads. Putting on higher profile tires is a cheap fix but unfortunately, your clearance may not allow it.The other cheap out is spring stiffeners. You’ll love the ride. 
I installed a set of Thrush side pipes and I can’t get over the speed bumps at the mall.
The car supposedly only had 63K original miles on it when I purchased it. That is not a lot of miles I would think to wear out a set of springs. But I guess they could be. Not a real fan of the spring stiffeners. Not as young as i used to be.I tend to like the smoother ride.
Man, you have nothing left !!! It sounds like an “I knew and old lady who swallowed a fly” situation which is owner induced and sometimes best solved by avoiding malls or removing the culprit.
PS…I like your taste in cars but Other than raising it “on demand” with air shocks, anything else would compromise the handling and looks of the car IMO.
I’m down to my last Corvette which is a '69 big block with factory side pipes. It’s hard to tell from the pic but that doesn’t look any lower than mine. Price you pay for the side pipes dude. You’ll have to choose between cruising the mall for cougars or driving your Corvette 
Lifting it would be lame. Dagosa summed it up pretty good IMO.
Yes the bottom line is to bite the bullet and invest in new suspension. May help a little bit.
If you want these side pipes, you should install a hydraulic suspension. Then you can raise the car to negotiate the speed humps and the occasional high driveway while still keeping the low profile on the street. I’d hate to compromise the excellent handling just to drive over speed humps.