In the past few issues of Street Rodder, we've looked into what it takes to bring a '49-51 Ford coupe up to contemporary drivability standards, including the installation of a new powerplant, steering components, and disc brakes. But all of this work was done with the stock chassis and, specifically, the vehicle's original front crossmember.
It seems that swapping front stubs on a hot rod goes back as far we can remember. In fact, Street Rodder even ran an article in December of 1973 that showed how to adapt an independent front suspension from a Toyota! Fatman Fabrications, based in Charlotte, North Carolina, has been building their own line of chassis and suspension pieces since the '70s and has become a leader in the street rod industry in the process.
In the past few issues Fatman's owner, Brent VanDerVort, showed us how to update a '49-51 Ford chassis with parts he and others offer, but this month he walks us through the procedure to completely remove and replace the front clip of a shoebox Ford with one of his company's affordable IFS frame stub kits. Fatman offers a wide selection of fitment, too, with stub kits from Studebakers to Lincolns, Chevelles to Dodges, and many more in between.
We're ready to get started...
We're ready to get started with the original frame set up on stands and leveled out, both front to back and side to side.
All you have to do is provide Fatman with your axle centerline and radiator core support measurements and positions (on their website they have a detailed worksheet to help you locate where to take all the measurements) and they'll build a stub for you. And after the work is done, your old sheetmetal should fit right back to where it was before you started.
The basic Fatman stub kit starts at under $1,000, but various options (such as stainless steel A-arms, coilover shocks, dropped spindles, a sway bar, and more) puts the kit in the $3,000-to-$4,000 range. Still, without the expense of having to blow your body off your chassis and completely disassemble your car to do so in order to get a completely new chassis, this frontend stub kit is a quick and easy way to get contemporary suspension and drivability (read as reliability) without going whole hog.
Also, if you don't feel like tackling this work at home yourself, you can have the project sent to Fatman Fabrications, as they also offer in-house fabrication and repair work. We followed along during a typical remove-and-replace session at their shop, and the work took less than four hours to do, not counting removing or assembling any of the sheetmetal.
Next we locate the front radiator...
Next we locate the front radiator core support mount hole and use a plumb bob to mark its position on the garage floor.
After marking the position...
After marking the position of the core support hole, we also find its height from the floor, noting the measurement next to the mark. The position of this mount controls the fit of the entire front sheetmetal assembly, so pay attention when marking these measurement points.
We also use the plumb bob...
We also use the plumb bob to define the position of the front bumper holes, running the line through the center of both front and rear bumper boltholes.
The distance between the floor...
The distance between the floor and each of the four bumper boltholes (two on the driver's side of the frame, two on the passenger's) is also noted on the floor of the garage.
Always measure to the center...
Always measure to the center of a bolt or hole, just like you would when using a center punch before drilling a hole. Mark a point on the top of the frame three inches forward of the forward-most body mount bolt.
Transfer the mark on top of...
Transfer the mark on top of the frame to the side of the frame using the plumb bob, creating a vertical cut line for when the front section of the original stub is removed.
We used a plasma cutter and...
We used a plasma cutter and a steel guide for the actual cuts. A torch or reciprocating saw can also be used, but care must be taken to make the cuts as straight and clean as possible.
While Brent VanDerVort steadies...
While Brent VanDerVort steadies the frontend with a floor jack, the final cut is made by Fatman Fabrication's Mike Casanova.
After the last cut, Mike and...
After the last cut, Mike and Brent remove the old frame section in one piece.
Mike goes back to clean up...
Mike goes back to clean up the slag, straighten the cut, and remove any paint or rust in preparation for fitting and welding of the new frame stub.
Using a hammer and dolly,...
Using a hammer and dolly, Mike taps out some small dents on the lip.
Fatman supplies tabs to fit...
Fatman supplies tabs to fit inside the frame ends to reinforce the weld area and to sleeve the joint. The tabs need only be tack-welded at this point as the finish welding happens later.
In another part of the complex,...
In another part of the complex, Fatman Fabrication's Jeff Watts does the final welding of the new frame stub, attaching the upper control arms that are mounted on a fixture surface plate.
This is Fatman's prefab'd...
This is Fatman's prefab'd frame stub, ready to be installed. Note the lower control arm mount extensions are installed, along with a large notch in the crossmember to make the various engines easier to mount.
Here Randy Beaver stepped...
Here Randy Beaver stepped in for Brent to help Mike set the new frame stub in place.
After rechecking all the core...
After rechecking all the core support, axle centerline, and bumper mounts locations, we found we needed to trim another 1/4-inch off the old frame to get the new stub to fit correctly.
A floor jack was used to do...
A floor jack was used to do the minute adjustments to the stubs' location before everything gets tack-welded.
As specified in Fatman's instruction...
As specified in Fatman's instruction sheet, we now have a 1/4-inch gap, backed up by the sleeve tabs, which will ensure full weld penetration. After a final check of those location measurements, the stub is welded in place.
Here we've welded the top...
Here we've welded the top side of the frame and ground down the side to show the next few steps. To ensure no warpage or shrinkage occurs, weld just a portion of each gap, alternating to another portion of the frame frequently. This also prevents any chance of shrinkage from pulling the stub out of position. (Brent says it's a good idea to do this welding while working on another project to avoid getting impatient for the gradual welding and cooling cycles).
The new Fatman frame stub...
The new Fatman frame stub is now completely welded to the old frame and ready to mount the new suspension parts. Be especially certain to use anti-seize on all the stainless steel fasteners as directed!
After only four hours of construction...
After only four hours of construction (including extra time to shoot the photos), we've added QA1 coilover shocks, a polished stainless steel control arms, a power rack-and-pinion, and a disc brake system from ECI. Soon this beast will be back on the road!