70-73 Early 2nd gen F body 1/2" Lower control arm mount reinforcement kit click for more pics and product details
The Lower Control Arm mounts on the 2nd gen F bodies weren't a great design. Side forces from cornering etc. are transferred to the edge of the sheet metal the sub frame is stamped out of by the LCA mounting bolts. To make things worse the stock bolts contact the frame through the threaded section of the bolt on one side of each bolt. The 70-72 and many 73's had smaller 1/2" diameter LCA mounting bolts which didn't provide enough area for the forces transmitted and GM started using larger 9/16" bolts sometime during the 73 model year presumably to help reduce the problem.
With the side loads modern aftermarket suspensions and/or tires can create the factory 1/2" mounting holes in the sheet metal the stock sub frame is made of is easily overloaded and damaged. This kit is designed to spread the shear force exerted by the lower control arms and stiffen the mount area to reduce flex. Kit can be used to repair damaged LCA mounts for applications where the stock LCAs will be used as well as applications where stock or aftermarket lower control arms which utilize 1/2" diameter bolts and the stock frame mounting positions.
Standard kit comes with a combination of custom fitted pieces and grade 8 washers that welded to the sub frame along with grade 8 bolts and correct distorted thread nuts. Our 1/2"" LCA tool (available separately) is highly recommended for use with this kit.
73 owners! Measure your stock LCA mounting bolt diameter so you know whether your starting with the earlier 1/2" diameter style or the later 9/16". This kit is the earlier 1/2" diameter.
NOTE: If you have an early 2nd gen (70-74) and will be using stock or aftermarket control arms which use 9/16" hardware you will need our early 2nd gen F body kit with 9/16" hardware. Also, if you have an early car (70-73)which originally came with 1/2" bolts and you are installing later stock arms or aftermarket arms that require 9/16" bolts you will need to drill out the mounts on the sub frame for the larger diameter hardware before welding on our 9/16" kit. The kit sold on this page is only for those applications where 1/2" diameter hardware will be used. Any questions contact us before ordering.