A smooth, level floor and an understanding of basic geometry will go a long way toward being successful with a front frame swap. A few decades of building round track racing frame experience would also help. We've done lots of "front clip" swaps where a damaged front frame section is cut away just behind the firewall area and another one grafted on, with nothing more sophisticated than a 4 foot carpenter's level, a framing square, and a plumb bob or three. Measure, tack weld, and measure again- - - -repeatedly, before you commit to doing a final assembly. A small angle grinder and a thin cutoff wheel is a lot more accurate than a cutting torch- - - - -make the initial fit-up as clean and accurate as possible. Putting a few chain anchor bolts into that floor and using screw-type adjustable jack stands also comes in very handy while assembling a frame.
Jerry
