Through the construction of our Project XS '70 Chevelle convertible and '55 hardtop, we've learned more than a few things about what really goes into building a car. Not just the nuts and bolts of it, but into the murky depths of what it takes to assemble a really cool Chevy.
Before a car can be wheeled into the paint booth for some color, there are important and sometimes critical things that need to be checked, test-fitted, and looked at. If you can avoid it, you never want to be drilling or cutting on a painted body. It's too easy for a tool to slip or similar mishap that'll add hours more work to your build, and ding your wallet for what it costs to fix the damage.
Now, if you're a pro builder obviously you're going to know most of what we're about to discuss. You might even think of something we didn't mention. If you do, head on over to the Super Chevy Facebook page, and post your dry-building hints and tips for everyone to see.
With the help of Classic Automotive Restoration Specialists' (CARS) Jim Barber, we're going to throw some tips out there that'll help make the build process easier for the at-home guy and help those with cars being built at shops better understand what's going into their car's construction.
Know Your Parts Ahead of Time
Building a custom car is a lot like cooking. You've got to know your ingredients beforehand and have them ready to go before putting everything together in the pot. If you're building a custom dash, you need to have the gauges in hand so you can build the structure around them. Do it in reverse, and you've just limited your options while probably increasing cost.
What wheels are you using? A lot of custom and aftermarket wheels require more clearance than what stock wheelwells can give, requiring mini-tubbing out back and mods to the inner fenders up front. For steering, wheel width is going to affect your turning radius and range, possibly requiring bumpstops to prevent rubbing.
Aftermarket A/C, stereo, and other accessory systems usually require dash mods and tweaks for proper fit. Installing power windows that weren't originally there? That means test-fitting the inner mechanisms and drilling holes in the doors and body to run the electrical wires.
Converting to aftermarket seats? A late-model transmission? Installing an aftermarket or custom center console? Odds are modifications will be necessary to the floor pan, seat mounts, and trans tunnel.
The list could go on for pages. The bottom line? Have as many of your parts in hand as possible, or at least their measurements, so you can get an idea of the mods necessary before paint. Here's Jim's take on this aspect:
"Have out all your parts first. This allows you to test fit everything prior to paint as the building process moves forward. Whether a custom build or stock resto, the finished product will be head and shoulders above the competition by dry building."
"Sure, test fitting sounds like twice the work. But in today's world of reproduction parts, if all of the manufacturers are to the edge of their tolerances, without dry building before paint, you may find yoruself shimming, cutting, grinding, and even slotting holes to get the proper fit," Jim says as a note of caution.
There are several aspects to this one, from checking fitment on a new chassis going underneath your car to making sure you're A/C unit fits correctly underneath the dash. In the case of the '70 convertible, the Vintage Air climate unit requires two tabs be secured to the firewall for proper mounting. To make sure the unit would be nice and secure, the shop went ahead and welded them to the firewall—something that wouldn't have been possible if the body had already been painted. Then there were the modifications to the firewall for running the A/C and heater lines, requiring further mods to the firewall.
Both of our project cars have had full aftermarket chassis installed in place of the factory originals. For the Chevelle, we had the prototype Art Morrison Enterprises '68-72 A-body chassis. One of the newest pieces out there, the AME unit bolted to the body a bit differently from the factory frame, require some test-fitting and tweaking to get everything just right. Our Fatman Fabrications chassis underneath the '55 has been in production for a few years, so the necessary mods for fitment are listed in the instructions. It still required some small mods for an exact, proper fit, but they were a known quantity.
Checking drivetrain fitment during the dry-build process requires the engine/trans to be installed and removed several times on a custom build. On a painted car, you only want to be installing the engine once, because each time it comes out increases the odds the paint will get nicked. This process also lets you check firewall clearance with the engine. Even though the Chevelle came with a big-block from the factory in '70, throw in our aftermarket chassis that tucks the body in closer to the frame, and you could have issues that require cutting and welding on the firewall.