34 Ford body
Start with the fuel tank cover at the rear and fit the top side where it joins the body perfectly. and clamp it in place. Level the body on jack stands and figure out some way to clamp the rear fenders temporarily in place so that follow the radius of the body wheel well and clamp to the fuel tank cover. Check that the outside of the fenders are vertical. Clamp the running boards in place, install with two bolts, the front inner fender panels. Radiator should be installed at this point. Install radiator grill shell, then place hood top and side pieces in place using clamps. Hood pieces should need some fitting by carefully removing metal at the rear of the panels, but do not grind on the hood at this point, final hood fitting will be done later. Block and shim the hood so the body & hood belt line lines up. Attach front fenders with a couple of bolts and carefully examine the "Look" of the car, running boards level across the top, stand at the rear and look down the side, are the front and rear fenders sides verticle, are the rear trailing edges of the fuel tank cover and fenders in a straight line as viewed from the rear. If everything fits up fairly well then stop and focus your attention on the engine fit-up. Install the engine and tranny and do a preliminary check of drive shaft alignment, if you have to raise the rear of the tranny you may need to modify the tranny tunnel of the body for clearance. if all is good to this point, give careful thought to how you will cool the engine, electric fan or mechanical. Fit your cooling components to insure engine clearance at radiator and firewall. Engine must fit the chassis and body must fit over the engine before any final fit-up of body parts. Determine the centerline if the hood and the centerline of the body, using a string through the front and rear windows, insure the centerline is correct. Make sure the hood belt lines, line up with the body belt lines. Insure the grill shell is verticle and fits the hood top. With hood sides temporarily attached check fit at front and rear of hood sides and adjust inner fender panels for fit at the bottom of the hood side panels, remember that hood fit must be done at the rear of the pieces not at the rolled edges. The hood fit is hard to get just right and you may need to revisit this later on. Then remove all the fenders, running boards, etc. Make sure the body is bolted in place. Go back to the rear of the car and start again with the fuel tank cover and rear fenders and perfect fit by grinding, sanding or fiberglassing. Two things to keep in mind during this stage, the parts must fit with minimum hand pressure, if you use a bolt to pull it in place, there is stress here and a crack will develope here with vibration from driving, and secondly, your parts will grow in size between every joint, because of paint film stickness (one coat epoxy primer, three coats surfacer, three coats of basecoat, six coats of clear). Work you way to the front, perfect fitting, body parts. If all is perfect the front fenders will roll under the grill shell and meet up in perfect match, if not, make them fit or use the little joint cover available from Yogi's. You may have the fender parts on and off several times until you get the fit-up that you like. Once you are satisfied with the fit-up and everything is bolted in place, then and only then should you attempt to fit the hood by grinding off the rear of the parts. Depending on whose body you are using you you may need to do some serious fiberglassing because you will grind away the original. Bodies by Outlaw, or *******, require only sanding to fit, some others will require a gallon of resin and yards of cloth. I hope you dont have one of those, this should help you get started on your project.