The frame on my 71 Stage 1 GSX is also a Hayes 1237139 and is dated 2/12/71 "3" The Body Build date is "04B" What you are seeing here is a "batch" of parts. Again, because there were so few 71 Big Block Buick A-body Coupes built it would take a while before a batch was used up and another was needed. As the model year progressed the dates of the parts will get further and further apart from the Body Build date, then another batch is made, the parts now are closer to the Body Build date, and then the cycle repeats. To put this into perspective at the end of the 1970 model year the Stage 1 distributors had a certain build date on them. They made so few Stage 1's after that, that the same batch of distributors was used all the way until the end of the 1972 model year. Now you will not see this type of thing with the 70 model year parts as they made so many more BB Buicks that year. However, you will see this same thing with the obscure options produced in that year, like the 15" steel wheels with the G60-15 Polyglass GT Tires and trim rings. Hope this helps. Duane PS. Does anyone know what caused the huge drop-off of Big Block cars for the 71 model year? This is a quiz as I know the answer.
So I assume the number I'm not able to read would be from the same batch. Thanks for the time and your input. I would guess insurance issues.
Dwayne, You are correct. I have a Magazine article from late 1970 where they talk about how high the insurance policies were raised. At that time a new 71 Small block car was the same price to insure as a Big Block car was in 1970, and the BB car insurance was going out of sight. Duane
just checked my 1971 flint built big block GS convertible the numbers are 3992389.built by hayes with a build date of july 15th 1970 shift 2. I saw in another thread that smallblock hardtops are3992388.Weren't all convertibles built on b b frames? this part number 3992389 doesn't match 1237139 could the difference be the build date?
Rick, the 3992389 = Code CS all 3400 & 4400 series convertibles. 1237139 = code BA 3400 series HT with 455 non convertibles. (71 BTN Book frame ID on page 27)
Rick, yes I'm planning on being there but if you want to look or get one quicker: https://gsbythenumbers.com/shop?olsPage=products Thanks, David
