Mine really isn't either Patrick. However I like the look of clear one better than the black top one, or the generic looking aftermarket ones.
There was an overflow available over the counter or dealer install for 68 and 69 if you were looking for more date correct. The 70 definitely works though.
I bought a black top one for my '71 GS from Cars many years ago. It was super nice, and I imagine these are just as good.
Here is some info that will help you figure out when this part was used on the production cars. Richard Lassiter asked me to do this article for the GSCA newsletter. It is offered here as a guide, Enjoy Duane 1970 SKYLARK/GS PARTS CHANGES If you work with 1970 Skylark/Gran Sports for any length of time you will notice that quite a few parts changed during the production year. The most obvious changes include the radiator cover plate, radiator overflow jug, rear courtesy light lenses, instrument panel lenses, and the height of the numbers/letters on the instruments themselves. Now that more and more people are interested in restoring these cars correctly, I am often asked when these changes took place, and if these parts changed gradually or happened all at once. To answer this I compiled data from talking to hundreds of original owners and looking at many unmolested original cars. I also took both the body build date (Located on the ID plate on the firewall.) and the various production plants into consideration. By doing this I discovered a few things; (1.) the production plants introduced the new style parts at different times, (2.) even weeks after the new style parts were introduced some cars were still being built with early style parts, and (3.) as time progressed the ratio of early/late parts decreased, until at the end of the transition period, only 1 early style piece could be found on any particular car. Below is the time sequence for these parts. Cars built on or before week 11D would have been built with only early style parts. Early Style Parts, Up through 11D (4th week of November 1969) Plastic Radiator cover, with metal end caps, and associated emission decals. Clear Top and Bottom Radiator Overflow jug Tri-shield Courtesy Light Lenses (4-tab) Pointy Instrument Panel Lenses Tall Numbers/Lettering on Gauges Transition Period (Week 11E thru 01A) Starting week 11E some later style parts were introduced. At first the cars had only 1 or 2 new style parts, but by the end of the transition period, the reverse was true. Later Style Parts, after 01B (2nd week of January 1970) Metal Radiator cover, with associated emission decals. (Edit, we now know some of the early style emission stickers made it on to the early steel covers.) Black Top with White Bottom Radiator Overflow jug Concentric Circle Courtesy Light Lenses (4-tab) Flat Instrument Panel Lenses Short Numbers/Lettering on Gauges By week 01B the changeover was basically complete, so cars built after this would have been produced with only the later style parts. The above info is offered as a guide only, there are probably exceptions. Duane Heckman
As to your retrofitting an overflow jug on a 68-69 car, I would imagine the style used would have been determined by when the job was done and what parts GM had in it’s Parts Division at that time. Duane
I thought I had scanned the 1968-1969 Buick bulletin about the radiator retrofit. In that bulletin, it lists the part numbers for the overflow jugs. The part number came back to the clear top tank. I will see if I can find the article when I get home...
Mike, Whenever you are around IT IS A PARTY. I wish I could put on the “emogies” from my phone. Today is actually a party. I am getting my 69 back today, so that might necessitate a ride. In less then 10 minutes I will be smiling and anyone within 5 blocks will know I was there. She is not really what I would call quiet. Duane
Duane, HA! Good to hear! I'm heading to NJMP in Millville, NJ Saturday to see my friend go around track with his 302S, not as exciting as your 69 Buick straight line action! Enjoy. Mike
I guess it's tough to gauge what the "correct" color was unless we took a time machine back to a Buick parts department late in 1969. Nonetheless, this is a fantastic reproduction piece, with the correct font in the correct spot. Dano grabbed me an NOS lid at the Nationals a couple years ago that's the same color as Brad's. I still may grab one of these new ones just to have in stock. This is mine:
I bought a used repro several years ago that was quite yellow. I soaked it in pure Clorox bleach with the to off for about two days and it came out like this. Lettering is wrong but otherwise, it's pretty close in color.
A while back I sent Glenn a decent clear top to use for repro project. Thanks to CARS for making the effort to produce them. All of should supoprt their efforts. So they can do more cool stuff like this.