An original Model A chassis is a surprisingly weak item, designed to twist somewhat with the stock suspension, and only surpassed in the flimsy stakes by the Model T frame. Unlike the Model B, with 6-inch-tall main 'rails and a K-member, and later Ford chassis with a full X-member, the Model A chassis had 4-inch-tall C-channel main 'rails and only one pressed steel crossmember in the center. If you're planning any kind of performance upgrade, and don't want to use an aftermarket chassis for a Model A, be prepared to spend a few days with a welder and grinder to stiffen the frame and add crossmembers.
As with the boxing plates we showed you last month, it's possible to fabricate crossmembers yourself, the most common way being to use box section steel. But once again, Dagel's Street Rods can save you a lot of time and effort, with their Super X crossmember. No ugly heavyweight box section affair, the Super X is 0.100-inch C-channel, with laser-cut holes. Designed to fit both stock and aftermarket Model A chassis, the Super X is supplied with a brake master cylinder mount, as well as a bolt-in transmission mount. Once I'd boxed my stock chassis, the Super X was a breeze to install, though I had to modify it slightly for my application.
With the reduced ride height provided by the kicked up, or Z'd, chassis, it's unlikely I'll be able to use the master cylinder mount supplied by Dagel's, owing to ground clearance issues, and the trans mount will also be surplus to my requirements, though I will likely modify it to suit. However, the biggest problem with the lower chassis is that the driveshaft now has to pass through exactly the same place as the center part of the crossmember, and this is where I had to modify the kit accordingly. However, it's a minor detail, and easy to overcome. Overall I'm extremely pleased with the quality of the Super X and its ease of installation. While manhandling the chassis around and placing it on jackstands toward the end of the work shown here, I noticed there's absolutely no "give" in the chassis anymore. Pick one corner up and the opposite corner lifts too. Even with the block and trans resting on the frame, it was possible to remove one of the jackstands from under the front of the chassis, and it didn't twist. Try that with a stock A frame!
This is the Super X crossmember...
This is the Super X crossmember from Dagel's Street Rods, which, coupled with boxing plates, transforms the rather flimsy Model A chassis into a substantially stronger foundation for a hot rod. The kit can be supplied with options for power, manual or no brake master cylinder, as well as a brake, brake/clutch, or no pedal assembly.
Before installing the Super...
Before installing the Super X, I wanted to ensure it would provide adequate clearance for a TH350 trans. As a Model A has a short wheelbase, and as such the trans sits a fair way back in the frame, this is especially important. Knowing I required 8 inches between the rear face of the radiator and the front of the engine block for a water pump and fan, I knew how far back to temporarily place the block and trans. Clamping the Super X side 'rails to the top of the chassis in their recommended positions showed the trans would indeed fit between them.
Up to this point the boxing...
Up to this point the boxing plates had only been tacked in place, and now came the laborious job of fully welding them and dressing the welds. The welding was tackled in short sections, allowing each to cool so as not to create too much heat build-up in any one area.
Once the welding was complete...
Once the welding was complete a coarse softpad on a grinder was used to dress the joints, transforming the C-channel original 'rails into a much stronger box section. With this task completed, the Super X crossmember could be installed.
It doesn't look like much...
It doesn't look like much but there's an awful lot of welding and grinding to get to this stage. Still welded to the jig, I removed the upper front and lower rear temporary crossbraces. The former had to be removed to trial-fit the trans, while the latter had to come out to allow the crossmember side 'rails to be installed.
It doesn't look like much...
It doesn't look like much but there's an awful lot of welding and grinding to get to this stage. Still welded to the jig, I removed the upper front and lower rear temporary crossbraces. The former had to be removed to trial-fit the trans, while the latter had to come out to allow the crossmember side 'rails to be installed.