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The down tube in this water neck was rusted but I managed to remove it. I've read on this site that the aftermarkets are poor quality or don't line up correctly so am hoping to keep it. But open to suggestions.
Has anyone tried to do a similar repair to install a new pipe and can share tips?
there are two versions out there that I know of. I bought that GM #12302551 from Year One years ago and it was slightly offset as the OP said and it did not fit my 71 350. Ended up tracking down GM #409037 on Ebay, which is a perfect fit and called out in the parts manual. The 12302551 was used on Cadillacs, etc.
there are two versions out there that I know of. I bought that GM #12302551 from Year One years ago and it was slightly offset as the OP said and it did not fit my 71 350. Ended up tracking down GM #409037 on Ebay, which is a perfect fit and called out in the parts manual. The 12302551 was used on Cadillacs, etc.
It was likely used on Cadillacs that were equipped with Oldsmobile engines. 12302551 is the supersession part number for Oldsmobile. Whether it fits exactly the same or not, that's another issue. But that's the part number to replace 409037. You don't want to use it, fine by me.
Thanks for the replies. Buying new is easier probably precovid or when you could walk into a store and purchase.
After some research, wanted to share what I did. I took a 1/2" NPT tap and ran in through the bottom. Took a Dorman 56360 heater fitting ( 3/4 In. Hose X 1/2 In. Npt X 1-3/4 In. Long Nipple) and threaded it in with pipe sealant making sure it's only on the threads. Fits perfectly but will need to use a Gates 20333 coolant hose like on early cutlasses, etc.
Somewhere along the line I read that Olds changed the early rubber “J” hose to later design with the “J” bend made in steel because the “J” hoses had a higher failure frequency.
The later part was a simple straight hose from the “J” bend to the water pump.
So, by making the “J” curve in metal they arrived at a more durable design with fewer in service failures.
I suspect the later design works better. But I’ve never had a failure in my early, rubber. “J” hoses.
If you’re going aftermarket, go for a straight hose. If going for originality with mid-60’s, a factory a “J” hose is your friend.
