Does anyone know when they switched from plastic to metal or metal to plastic? The reason I am asking, I have a 72 GS built in Framingham plant. It has a very early build date (I think Oct 71). This car is completely unrestored and had been sitting since 1980 when I purchased it. It was built with the clear top radiator overflow and has a plastic radiator cover with no stickers on it. My other 72 GS that someone else restored was built in California plant (build date Apr. 72) and has a steel radiator cover. Did it depend on the plant it was built in, the early build date, was plastic used on 71's and because of the build date it got leftover parts? Doe anymore have an idea?
I talk to Duane every morning on his drive to work, but I know too. The switch from plastic to steel occurred very early in the 1970 calendar year (think January/February time frame) along the same time that the black top overflow and flat instrument lens' came into being. By 1972 model year, they had long been using steel and black top overflows. While I will "never say never", I don't believe your car was originally equipped with a plastic cover or clear top. My best guess is the car was involved in a collision early in it's life and used parts were used, or even crash parts from GM and the person that pulled those parts picked up a plastic top. My bet is on a collision and used parts were procured for the repair and the front "clip" with the clear top and plastic cover came from the same wrecked early 1970 model year Skylark.
I'll have to take a look at the wheel well and the radiator support to see if that is a 1970 style. The hood, bumper, and grille are all 1972.
The mystery continues. The build date is Oct. 71. It has a 71 (stamp date) on the radiator support and the wheel wells are 71-72. So it may have used parts on it but if it was in an accident you would have thought the radiator support would be a 70 to match the radiator cover. Now what, do I change it to be what most 72's are or go with what's on it and assumed it is correct. The factory could have put these left over parts on. Does anyone else have an early build GS from the Framingham plant that is unrestored?
This is interesting. Mine is a January 1970 build date with clear top overflow, plastic radiator cover and flat lenses - with "tall number" tachometer.
Your car has early 70 parts on it. By the end of the 2nd week of January 1970 (for all plants) the clear lid overflow, the pointy lenses, the tri-shield courtesy lights, and the plastic rad cover were all replaced by the newer parts, ie. the black lid, flat instrument lenses, concentric circle courtesy light lenses, and the metal cover. Your rad support should be stamped 71 because the part was first made for the 71 model year and was not changed for 72. .......................so if you want to be correct ditch both the rad cover and the overflow, because they are not correct and must have been replaced. Also, when you get the new rad cover make sure it is for a 72 and not a 70 or 71, as they are different. Duane
Duane, Was each year different or was 70/71 the same and 72 was different? Does anyone have pictures of the correct 72 radiator cover?
Brett, They did have different part numbers. I found an old post where Duane listed all the part numbers for each year. per Duane: 1970 Components Water Pump, 350 all, short shaft, # 1374877 Water Pump, 455 non-AC/Std. Cooling, short shaft, # 1372812 Water Pump, 455 AC/H.D. Cooling, short shaft, # 1386961 Radiator Core Support # 1231398 (Number stamped into the upper bar) Top Cover, early style # 1232819 (Plastic with Steel end caps) Top Cover, late style # 1234369 (All Steel) Fan Shroud, Small Block # 1232996 Fan Shroud, Big Block # 1233000 Rubber Insulators # 1387423 (LT, RB) (Cast into part) Rubber Insulators # 1387422 (LB, RT) (Cast into part) 1971 Components Water Pump, 350 all, long shaft, # 1235958 Water Pump, 455 non-AC/Std. Cooling, long shaft, # 1380118 Water Pump, 455 AC/H.D. Cooling, long shaft, # 1233531 Radiator Core Support # 1237210 (Number stamped into the upper bar) Top Cover # 1237506 (All Steel) Fan Shroud, Small Block # 1234555 Fan Shroud, Big Block # 1234484 Rubber Insulators # 1236777 (LT, RB) (Cast into part) Rubber Insulators # 1236778 (LB, RT) (Cast into part) 1972 Components Water Pump, 350 all, long shaft, # 1235958 Water Pump, 455 non-AC/Std. Cooling, long shaft, # 1380118 Water Pump, 455 AC/H.D. Cooling, long shaft, # 1233531 Radiator Core Support # 1237210 (Number stamped into the upper bar) Top Cover # 1240323 (All Steel) Fan Shroud, Small Block # 1238972 Fan Shroud, Big Block # 1238973 Rubber Insulators # 1236777 (LT, RB) (Cast into part) Rubber Insulators # 1236778 (LB, RT) (Cast into part)
I think it had to with the holes for the sight glass for the AC cars. If memory serves correct, and I am probably wrong, I think 70 had no holes, and there was 1 hole for a 71 and two for a 72, but someone would need to check that. Duane
I'm pretty sure 70 had one hole, 71 had 2 holes and 72 had more. I think you are a bit rusty Duane! But great to see you responding back on this tough stuff.
While taking photos and notes of original, unrestored cars for many years, this is what I have observed about '70-'72 radiator covers: -'70: Three different covers used this year. Early cars used plastic cover with metal hold down brackets on the ends, then switched to metal with a single large hole, then late in the '7o model year another large hole was added near the first hole for a total of two holes. -'71: 2-hole cover all year - '72: the early cars had a metal cover with two holes (just like the '71 models) but at some point during the production year they increased the number of holes to four. We have a small fleet of '72 Buicks and the early cars have covers with 2 holes, while the later cars all have a cover with four holes. If your car was built in Oct '71 it most likely had a 2-hole cover like a '71 but if you install a cover with four holes it would function fine and would be accepted as correct for a '72 since the exact switch over to a 4-hole cover isn't known and they are what most of the '72s seem to have had from the factory. Good luck with your search. Here are photos of each of the four styles of cover, plastic, 1 hole, 2-hole, and 4-hole.
Not to sound opportunistic, but if you need to get rid of those incorrect parts (clear overflow and plastic cover), I'm more than willing to help you out. Was that passive-aggressive enough?
I have already had someone ask about them through a private message. The clear over flow tank is in bad shape but the plastic radiator cover with the steel ends looks great. I would like to find the correct replacement before I get rid of it but I will keep you in mind.
