A good deal of common sense must be exercised in the assembly of this unit, high quality welds are essential, we recommend Heli-ARC (TIG) Welding. If you are in doubt about your welding ability, we strongly suggest that you tack weld components in place and take them to a competent or certified welder for final welding.

1. Frame should be boxed in the area of crossmember attachment; areas adjacent to welds must be sandblasted or ground clean.
2. Set the frame on sawhorses or a suitable working area and level the frame from side to side using a good carpenters level.
   A) Front to rear frame "rake" can be set at this time. (See Notes)
3. Square the frame by cross measuring.
   A) Frame may be a parallelogram (one rail behind the other)
4. Removing existing rear crossmember:
   A) Tack Weld in temporary braces across the top and bottom of frame rails about 12 inches in front of crossmember.
   B) Measure width of frame: outside measurement (OD) will be approximately 34 inches at rear axle centerline.
   C) Repair or straighten as required.
5. POSITION WEEDEATER ADJUSTABLE CROSSMEMBER
   A) Trim required amount off WEEDEATER ADJUSTABLE CROSSMEMBER.
   B) Amount trimmed off depends on whether crossmember is butt welded to boxing plates, or placed on inside of edge of frame rails and welded.
   • For F-100 We recommend positioning crossmember inside frame channel and boxing around it.
   • Position crossmember approximately 1/4" below top of frame rail
6. Bolt crossmember assembly to top of Jag Pumpkin using the tapered seat OEM Jag Capscrews. (part # C17024 if you don't have them).
   A) Narrower end of center mount plate to the rear of car.
   B) Assemble lower control arms to Jag Pumpkin using fulcrum mounts, shafts, washers and spacers. (See our Catalog or Jag Manual)
   C) Bolt Pinion Support Bracket to front of Jag fulcrum shafts at this time.
   D) Centerline of crossmember and centerline of 1/2 Shafts should coincide.
   E) Shock bosses on crossmember and Lower Control Arms (LCA) should be parallel.
7. Position crossmember between frame rails. (see NOTES back page)
   A) Vertical positioning of crossmember depends on desired ride height.
   B) For wheel base positioning: see NOTES
   C) Jag sedan pinion centerline will be parallel with the fulcrum shaft centerline.
   D) Jag XKE pinion centerline will point slightly upward at an angle of 5?60.
   ( XKE's can be converted to flater sedan angle): (See NOTES)
8. TACK weld crossmember in place: DO NOT FINAL WELD CM AT THIS TIME
9. Attach pinion support bars to front pinion support tybar.
   A) Clevis ends attach to pinion support tybar.
   B) Capture bushing ends with teardrop shape gussets, 9/16" bolts, washers and nuts supplied.
   C) Adjust length of support bars to position capture gussets to lower edge of frame rails.
   D) Tack weld teardrop gussets in place.
10. Check that face of shock boss on crossmember and LCA are essentially parallel.
    A) Bolt a shock to crossmember shock boss and Jag LCA.
    B) If shock won't line up with both shock bosses: You Have:
    • Assembled Jag Fulcrum Mounts to Jag Pumpkin incorrectly.
    • Assembled Jag center crossmember mount plate backwards.
      (small end of plate toward rear of car)
    • XKE Rear End instead of a Sedan Rear.
    C) Shocks line up correctly: ALL RIGHT !!
11. Stand around and eyeball your work; does everything "look" right and straight?
12. Final weld crossmember in frame. (Have you read the NOTES yet?)
    A) Read NOTES before final welding.
    B) Read All NOTES before final welding.

1. We recommend assembling bed and rear fender to frame as a check for rear tire centering and desired height in wheel arch.
2. Approximate measurement from bottom of frame to 1/2 shaft near outer U joint is: 5 1/2 inches at normal ride height.
3. Bottom of hub carriers should be approximately parallel to ground with frame at normal rake.
4. Normal Attitude For Jag 1/2 Shafts at Ride Height: 1/2 Shafts "Hang Down" Approximately 1 to 2 degrees (Outer Ends Lower Than Inner Ends)
   A) Check with Magnetic Protractor.
5. Yes, Dave; This is California: and we can turn straw into gold:
   send your old XKE inner Fulcrum Mounts and $ = We'll puss 'em out so's your pinion will lay flat too.
   A) Pinion centerline and All shafts should be parallel to each other in a side view.
   (BOTTOM of HC and/or HC shaft should be parallel with ground)
   B) This conversion is not possible with some 61 to 63 XKE's that have only two holes in each Inner Fulcrum Mount; your Fulcrum Mounts must each have 4 countersunk holes for this modification.
6. Miscellaneous measurements:
   A) 1953 to 1958 F?100 frame rails 34.0" wide.
   B) 1951 to 1952 F?100 frame rails 32.0" wide.
   C) Bed only outside measurement 49 1/2" wide.
   D) Rear fenders outside measurement 72" wide.
7. For coilover shock clearance, boxing plates must be set in at an angle at bottom of frame channel for a distance of 4" before and 4" after crossmember for a total of 11 to 12 inches on each side.
   A) See detail drawing of frame rail cross section.
8. If you are using an XJ Series Jag rear ( 61-1/2" wide ), the lower shock shaft tube in Lower Control Arm must be relocated 2 inches in from the stock XJ position: ( 12-1/2" cc from inner fulcrum shaft).
   A) This is necessary for shocks to clear inside lower edge of frame rails.
   We can do this for $150.00 + UPS Shipping)
   B) See detail drawing of Lower Control Arm.
9. See rear radius rod detail drawing.
10. See frame rail modification drawing for coil over clearance.

© Snow White Ltd 1989 (REV 3/91;3/92;6/92;6/94;7/04)