A. All front suspension and steering components (except the upper control arm mounts) must utilize the original O.E.M. suspension and steering component mounting holes. All mounting holes must remain a single round hole as produced by the O.E.M. Adjustable mounts and/or “slugs” will not be permitted.
B. Weight jacking bolts (wedge bolts) may be added to O.E.M. frame but, must be located within 1 (one) inch of the original centerline of the O.E.M. front spring location.
C. Unless otherwise specified, the front suspension components must be O.E.M. serviceable parts and originate from the same O.E.M. frame manufacturer for that application.
D. Unless otherwise approved, only O.E.M. and/or O.E.M. replacement type passenger car spindles will be permitted. Spindle O.E.M. manufacturer and model is optional. Fabricated spindles will not be permitted. Spindles must not be altered. O.E.M. spindles utilizing a removable steering arm must use the same O.E.M. steering arm originally supplied with the type and model of spindle being used or a fabricated steering arm that is an exact match (length, mounting holes, etc.). If a fabricated steering arm is used, competitors must be prepared to supply an O.E.M steering arm for an inspection comparison.
E. One side lower control arm must maintain the OEM dimensions. The opposite side lower control arm must maintain the OEM dimensions +/- one (1) inch. All fabricated lower control arms must fit the DIRTcar/UMP lower control arm fixture(s) with the exception of the length as described above on one side. The maximum outside to outside tread width measurement must not exceed 78”-inches.
F. The following approved multiple piece aftermarket spindles may be used for competition.
a. Speedway Motors: 91034313, 91034501/2, 91034511
b. Afco: 1063435L/R c. Argo manufacturing: RP-929 (AMC), Mustang II
G. Alterations and/or relocation of the lower control arm mounts will not be permitted. Lower control arms may be O.E.M. lower control arms for the frame being used or DIRTcar approved fabricated lower control arms, which are mounted in the O.E.M. location and maintain the O.E.M. dimensions. Lower control arms must be the same length when compared to O.E.M. right and left. The lower coil spring seat must be an integral welded component of the lower control arm. If using spherical rod ends (heim joints) as lower control arm mounts, spherical rod ends (heim joints) must be welded to the lower control arm to prevent adjustment. Competitors must be prepared to supply an O.E.M lower control arm for an inspection comparison. All fabricated lower control arms must fit the DIRTcar/UMP lower control arm fixture(s).
H. Tubular-type upper A-frames will be permitted. The upper A-frame mounting locations may be relocated. Aluminum cross shafts will be permitted.