The aluminum radiator used on 1961 and 1962 Corvettes uses only one General Motors part number, yet several changes were made during this two-year period. The most obvious difference is the upper cast neck used on 1961 models. This casting (part 3150896) included a raised square bump on the top of the casting. All 1962 models omitted this raised bump and the casting was flat but it retained the same casting number. Since this casting number is so obviously positioned, several people confuse this with the part number of the radiator. 1961 radiators were not painted until the middle of production. Late 1961 & all 1962 radiators were all painted black gloss enamel.
As a result of the different castings, we created our model 944 for 1962 model Corvettes. This radiator features the flat upper casting and has an expansion joint cut into the top plate. According to several original samples and the GM blueprints this saw cut was not introduced until 6-25-1961, which means no 1961 should have it.
There was yet one more major change to the radiator in March of 1962. The part number and date code, which was previously stamped into a metal tag, was now stamped into the top of the radiator. The aluminum tag was changed to be a stick on coolant warning and was carried over into the early 1963 model. These date stamped 1962 radiators were the only coolant system parts that ever used the month/year format instead of year/month that was used on all other years, including expansion tanks. The first stamped radiator was C62. Service parts produced after 1963 used the formed metal tank and tube assembly from the C2 instead of the upper castings.