The upper door bar can be tacked in place so that the upper crossbar can be located. When this is done, the upper crossbar can also be tacked in place. There is one more mounting bar, which should be located to the right side of the upper bar and then to the rollcage crossbar. With this tacked into place, the seat frame can be gently removed from the chassis.
Out on the bench, weld all joints. Weld part of a joint, and then go to the next joint and weld part of it. Repeat this process of moving around, partly welding joints until all is complete. This will minimize warpage of the unit and help to maintain its fit in the chassis.
Still on the bench, we fitted the Oval Craft seatback into the frame. All the mounting holes were drilled, and the seat was secured with 7/16-inch Grade 8 bolts. The bolt size may seem like overkill, but using a bolt this size allows the load to be spread over a larger area.
Now is the time to locate the attachment points for the belts. CSC supplies tabs for mounting all of these. We used some of theirs and some parts from A&A Manufacturing. From CSC we used two tabs on the front crossbar to bolt to the seat. Additionally, CSC's tabs were used for side seat mounting bolts, and one tab is used for a five-point harness on the front crossbar.
Belt Attachment
A&A has a new part, a "U" shaped piece used for belt attachments. You should always mount belts between two tabs, putting the belt attachment bolt in double shear. The A&A bracket lets us weld one tab in place and still have the attachment bolt in double shear. We used these for the lap belt holders.
For the shoulder belts, we did it two ways. If you have room, use the double shear bracket. If the seat is too close to the cage bar to allow the adjuster or mounting hardware to clear the seat, then use a single tab pointing down as shown in the photos. Be careful to mount all the belt hardware in the correct location.
We selected a six-point harness from Leaf Racewear. The lap belts should angle up at about a 45 degree angle from their attachment point. They should follow a path across the pelvic area of the driver. The mount should be located so that the belt does not pull against the edge of the hole where it goes through the seat. The double shear bracket here is nice to have because the belt hardware can freely pivot.
 The top rear seat mount has...  The top rear seat mount has been tack welded to the seat frame. This isan A&A part. It is bent in the middle to conform to the shape ofthe seat. To the right is the upper frame-to-cage crossbar mount. It has also been tacked into place. The frame is readyfor final welding. |
 The seat frame is now welded...  The seat frame is now welded in place to the cage. It isattached to the cage at three locations. All of the beltattachment points are welded to the seat frame except the shoulder belts. |
 The seat is ready to be bolted...  The seat is ready to be bolted in. Near the front edge, the seat restson the bottom crossbar. Notice it is cradled down between the side rails. |