These brackets hold the radiator in place using the S-10 rubber cushions (not included). These parts only work when installing the Corvette radiator in the forward position. They only work on the 1982-1993 trucks.
The parts shown above are the older style. The new parts, shown below, are made of billet aluminum.
Price from Stealth Conversions is $35 a pair, including shipping, Part #S10-125.