Finally dropped for the first time since it's installation in late 1968, years of grime, grease, and road debris had taken its toll on the K-member. A couple cans of degreaser helped to loosen much of the caked-on dirt. We also let it sit out under the hot Florida sun to break it up a little more.
We had a couple stipulations in mind when we decided to cut up our Charger's K-member. First was to open up the K-frame to allow enough room for our drag racing rectangle oil pan. The bulky pan measures a hair over 8-inches wide, a girth that wouldn't pass with a standard K-member. Opening up the K-frame would require most of our attention because the K-frame was also intended to act as a crossmember between the forward frame-rails. Cutting it up meant weakening its structure if we neglected to reinforce it, so we chose to "box" it in, making the newly opened engine cradle far more rigid and stiff than when it left the factory. In addition, since future plans for the handmade, homebuilt hauler included well over 700 hp from an angry elephant, we decided to run a motor plate, or elephant ears as it were.
Running a motor plate meant not having to use the factory engine mounts. This provides us with a couple benefits. First, our newly modified K-member would no longer be twisting under the torsional torture that our Hemi will be dishing out. Optimally, a high-performance engine demands solid motor mounts; most rubber or polyurethane mounts are prone to tear and shred under such conditions. The motor plate not only obliged with that need, but eliminated the use of the factory perches, allowing us the second greatest benefit-freedom to adjust our engine's placement.
Though we will be maintaining the Mopar-characteristic engine offset to ensure drivetrain alignment, we will be able to lower our Hemi ever-so-slightly to give us just enough clearance under a flat fiberglass hood. Of course, this puts our pan and headers in danger of being battered if we're not careful, but the allure of a 700-plus horse Hemi hidden under a flat hood is worth the risk in our eyes.
We spent two after-work afternoons (a single Saturday for most) working on this K-frame project, which resulted in a lightweight, structurally stout, modified K-member. Our only expenses were the price of two cutting wheels, a can of semigloss rattle-can paint, and scrap 12-gauge sheetmetal. Even with only limited welding experience, this job is an easy do-it-yourselfer for most any Mopar enthusiast wanting to customize their Mopar without sacrificing the stability of their ride. In fact, boxing in the modifications made to your K-member will not only slightly lighten it, but strengthen it substantially. But make sure to follow the fabricator's first commandment: measure twice, cut once. Too many times we neglected this and had to start our project over.
(Editor's note - Kevin, do you mean like your truck-procured Dana that is now cut too short?)
Using a straight edge and a white-out pen, we traced the pattern we would follow to relieve our K-frame of the extra weight. We kept the factory braces for the steering box and measured 5-1/2 inches to each side of the center hole. From there, we followed straight back and down the seams. We discovered that the small hole found in the top front of the K-frame was a near-perfect center point for us to measure from. | 
We ran our cutting wheel right along the lines. Using a plasma cutter does sound like a good idea, but the thickness of the K-member was too much for our torch to handle, that, and it would have made for a messier line than what we knew we could do with the cutting wheel. | 
Once the top was cut, we followed our same pattern on the bottom. Since the factory K-frame on a big-block B-Body comes with large relieves to alleviate excess weight from the engine cradle, as well as to let water and road debris drain out, we planned on patching those too. the severed portion of our K-member weighed in at a hair over 3-1/2 pounds. combined with the hefty engine mounts, that came in at a savings of nearly 6 pounds. Every little bit helps. |