In the late-'80s, gasoline and fast food hamburgers were relatively cheap, and the then-current Corvette (C4) was relatively expensive. During the intervening years, things have changed dramatically. The price of gasoline and hamburgers has jumped, while the cost of a '86-'88 Corvette has plummeted. That's perfectly understandable because Corvettes of that era are now just under or just over 20 years old, but, hopefully, that's not the case with the gas or burger you just purchased.
Unlike a hamburger from the same time period, a 20-year-old Corvette still has quite a bit of appeal, especially considering the price at which one can be purchased. But a 20-year-old car-even a Corvette-is still a 20-year-old car, and cost isn't the only thing that has changed in that time period. Improvements in engine, drivetrain, and electronic-control technology have dramatically altered virtually every aspect of the Corvette driving experience. Editor Alan Colvin and I had discussed the C4-C5 technology gap on several occasions, and during one of those discussions we began speculating about the possibility of combining the low cost of a well-used C4 with the powertrain technology found in a C5.
During a subsequent conversation, Alan said, "We get a lot of e-mails and calls from readers who either own a C4 or would like to buy one, and a lot of them want information about rebuilding or updating the powertrain. They're concerned about reliability because a lot of these cars have well over 100,000 miles on them."
Then he said he wanted to move beyond speculating about updating a C4. "Here's what I'd like you to do," he said, (notice he used the word you, not we) "see if you can find a C4 at a reasonable price, and then figure out what it would take to install an LS-type engine and a five- or six-speed transmission." Then he threw in the clincher-"I want to do it all for a total cost of $15,000."
A few days later, after several hours of searching on the internet and making phone calls, I found exactly what we were looking for-an '87 coupe with 140,000-plus miles on the odometer. It wasn't pretty; there was some body damage, and the interior showed definite evidence of occupation by a person or persons who were inappropriately dimensioned for the confines of a C4 passenger compartment. But the engine and driveline were in good condition (considering the mileage), and, more importantly, the price was right.
For the past few years, the previous owner's good intentions had been propelling him rapidly along the road to nowhere. His restoration project had more starts and stops than a New York City subway train, and he had finally thrown up his hands and just wanted the car to be gone. We were happy to give him $2,500 to take the car off his hands
After we had an appropriate project vehicle in hand, we then purchased a 5.3-liter truck/SUV engine to replace the existing, well-worn 350 Tuned Port. Having read that, the first question that probably comes to your mind is, "Why didn't they get an LS1 or a 6-liter?" The reason is simple-cost. Hundreds of thousands of 5.3-liter-powered trucks have been produced, making the supply of used engines plentiful-and that means cheap. Since Skinflint Colvin had set a total project cost of $15,000, we had to view every upgrade and modification in terms of the potential ROI (return on investment). We paid $700 for a complete 80,000-mile engine, including PCM, wiring harness, all accessories, brackets, and have heard of even better prices for similar packages. (Cost varies considerably depending on locale.) An LS1, LS2, or even a 6.0-liter truck engine goes for considerably more than that.
Aside from cost, a 5.3-liter engine offers another advantage over an LS1 or LS2-a cast-iron block. Any engine with an aluminum block is obviously lighter, and that would call for some type of suspension modification to get the front end back down to standard ride height. Trading iron for iron eliminates that concern. The same would be true of a 6.0-liter iron-block engine, but then the higher cost of that engine rears its ugly head.
With each subsequent discussion, the 5.3-liter engine became more appealing. Its SAE net horsepower rating of 285 is 45 hp more than the original '87 engine produced. So a significant performance improvement is at hand after installing a bone-stock 5.3. With a cylinder head clean and a mild cam, net horsepower jumps to well over 300. That represents a lot of horsepower per dollar.
Now that we're ready to proceed with the project, we'd like your input. If you had a total budget of $15,000, ($11,800 remaining), what components would you choose? Specifically, we'd like you to indicate type and brand of headers, camshaft, intake manifold, clutch/flywheel, shifter, brakes, suspension, wheels, tires, and anything else you care to mention. E-mail your suggestions for our C4orce project car to corvettefever.features@primedia.com and stop back next month to see how our project is progressing.