1963 lower radiator hose

[Steve K.]

The lower hose is being rubbed by the alt/wp/crank belt. There seems to be no way to get it to clear. The pulleys all line up, but the bottom pulley has three grouves and the wp only has one. This is a power steering car which has a separate belt from crank to PS pump. Maybe I need the correct configuration for the belts/pulleys on this 300hp engine!?
Help please....
Thanks,
Steve

[Mike M.]

Re: 1963 lower radiator hose

check and see that you didn't connect the radiator end of the hose to the H20 pump and vice versa. should be an arrow stamped on the GM hose which shows direction of coolant flow(rad to pump). mike

[Steve K.]

Re: 1963 lower radiator hose

I just found out that the 1963 water pump pulley is a double grouve even if only one grouve is used. Does that sound right? The GM part number is 3790356.
Also, is hard to find. This car has a 1966 single grouve pulley which sits back too far. Any advice?

[Jack H.]

Re: 1963 lower radiator hose

I think you'll find correct reproductions in the Paragon catalog priced reasonably (around $35)....

[bill #36445]

Re: 1963 lower radiator hose

Steve;

Just a thought since I seem to have the same problem with my '65. It turns out my '65 has a '66 core support in it that moves the bottom of the rad forward. It may be that the hose is being pulled forward to meet the lower rad outlet causing it to rub on the alternator belt. This is just a theory, in my case, since I know now that the core support is wrong. I'm not sure how correct your car is but it may be worth a look.

You can look down a few threads for a discussion on "Clutch Fan" to get a good description of the core support differences from both Michael Hanson and Jack Humphrey.

Also, I've noticed in some of the parts catalogs that some of the reproduction rad hoses have a larger kink in them where they enter the water pump than others. It could be that we both just have bad reproduction hoses and a more correct version may fix the clearance issue.

Good Luck!

Bill Jennings

[Joe L.]

Re: 1963 lower radiator hose

Steve-----

Well, I actually hate getting into some of these pulley configuration discussions, especially for 63-65 Corvette applications. However, I'll offer this.

The correct waterpump pulley for your application is GM #3790356. This is a 2 groove pulley notwithstanding the fact that I believe that the 63 AIM depicts a single groove pulley and it is of 7-3/32 OD. The GM #3790356 pulley was once available in SERVICE but was discontinued in July, 1974 and replaced by pulley GM #3900434. That pulley was, unfortunately, discontinued in May, 1990. So, there's currently no replacement available from GM. I think that the "Pulley King" reproduces it, though. It's always best to purchase his products from Corvette parts dealers that STOCK the item and have it IN STOCK to sell to you.

The correct crank pulley is GM #3744043. At one time, this pulley was known as GM PART #3747479 (although it was still stamped 3744043). It's a 2 groove pulley. Anyway, it's back to GM #3744043 now and it remains available from GM for about 40 bucks, GM list.

There are not very many GM PRODUCTION applications in which there are unused pulley grooves. It's just one of those things that doesn't "set well" with customers. If they open the hood, especially prior to sale, and note a "belt missing" they might lose confidence in GM. However, I do think that these 63-65 base and L-75 applications might have been some that did have unused pulley grooves.

Now, as far as the belt configuration goes, I THINK that this is how it was: the INNER track on both the waterpump and crank pulley were the unused ones (OR, a captive belt filled these grooves, but I don't really think so). The next track was the track for the belt that included the crank, waterpump, and alternator pullies. For power steering cars, I THINK there was the GM #3751232 add-on pulley for the crank. This pulley is also still available from GM. If you have a stamped steel power steering pump pulley (which may be stamped GM #3770509), then I think that your car almost certainly used the add-on pulley. Without it, I don't think that you'll be able to achieve a correct pulley alignment with the 3770509 pump pulley.

[mike cobine]

Re: 1963 lower radiator hose

Steve,

Joe Lucia and I went over these pulley numbers last fall, I believe. I can't remember the numbers and can't remember where those notes are right now, but if you do a search in the archives during last fall, I am sure they were appear.

I found several on eBay. However, like everything else on eBay, buyer beware. Know what you want, know what they are selling, and know what it is worth. I think one of the pulleys is still available from Chevy, around $45. This pulley was being sold as NOS on eBay for $50.

[Steve K.]

Re: 1963 lower radiator hose

Joe,
You are correct on all of your advice. I now have the correct pulleys in place, except the alternator pulley. And, wouldn't you know it is special to this configuration also. It is on order.
Thanks for your input,
Steve