I have a 70 Challenger I put a 31” wide aluminum radiator in. I am trying to find an upper hose that will fit this application. It is passenger side 1-1/2” and measures 13” center to center. Does anyone have a part number for something that might work?
Thank you in advance!!

Given the lack of part# responses, here is something you could pursue if in fact no such part exists: get the hose for the narrower rad, cut it in the middle and extend the length by using a coupler.

Haven't done so myself, but I've seen a few cars using this approach and it seems to work pretty well.

Buy some silicone bends (spendy) or cut up a stock hose, add the appropriately sized tube (swaged) and job done as per pic. I did pretty much the same on the lower hose to clear the oil lines for the remote filter

For a non-OEM deal like that, I'd make a pattern and check the hose rack at an auto parts store.
Pattern can be welding wire, coat hanger, cardboard template...whatever helps visualize & compare.
Also, bring measurement of ID (OD of necks) with you.
The photo makes me think something for a GM pickup '73 & later may work.

I used gates hose part # 21511. Just had to trim the radiator end. Keith

I do a lot of fabrication stuff and while it would be great if you could just buy something correct, I don't think it is available. What I do is take the measurements of the inlet and outlet sizes and bend a welding rod the shape the hose needs to be and go to the local parts store they turn me loose with my caliper and welding rod, 90% of the time I find a hose I can use or cut a section out of that will work. Then I write on the customer's ticket the part number of the hose for future reference.

You'll have to do some detective work to find a hose that fits. Mopar radiators were usually 26 inches but perhaps some trucks had something that was 31 inches. Do some radiator core research to find something that wide. If you can't find a Mopar that wide then you'll have to find another brand that used a wide radiator and a central mounted vertical water outlet. Not all engines used a central water outlet and some engines used a front facing or 45 degree angle outlet so you have to know what you're looking for.

My last build was a Duster with a big block. I put a C body radiator in the Duster so I had to search for a big block application with the C body radiator. Fortunately that wasn't too hard to find. You could use the same BB/C body upper hose and then lengthen it as needed with a metal tube.

weld a tube to your aluminum thermostat water neck towards your upper hose outlet and use a small radiator hose . that is that we did on my 68 charger with very similar radiator

i have one of those replacement "heat stove tubes" from a 70's something [universal perhaps ?]
i just bend it to whatever shape i need, then go to the local parts store [o'reily's and napa] and match it up to something on the wall.
most of the time the hose needs trimmed on both ends.
i also bend some 1/16" wire around a broom handle, then insert it into the lower hose to prevent it from collapsing if it wants to do that.

I know this thread is an old one but,any ideal on the lower hose (part #) on this car?

I don't like trusting a .50 hose clamps from blowing a hose going down the track. I welded up some -20 weld bungs and made some -20 AN upper and lower hoses.

On your deal with the radiator inlet being lower than the top of the upper hose I would make it have a filler cap at the highest point on the upper hose I could get, you need to be able to purge the entire cooling system of air