Gas gauge question GL1500 vs. GL1200

[oldmopars]

So, I am doing a bit of a mis-match build of a bike, mostly a 1200 with a lot of 1500 parts on it.
Can anyone tell me if the gas gauge from a 1500 will read correctly with the sender from a 1200?
Yes I know the complete gauge cluster will not work, I am making a custom one. I only want the Speedo, temp gauge and gas gauge. Very simple.
So, I guess what I need to know is are the resistance readings from the GL1500 sender and the GL1200 sender then same?

[AZgl1800]

no it won't:

why?

the float level goes up/dn depending on how much fuel is in the tank.

The tanks on the two bikes are very irregular in shape.

the 1500 is infamous for reading Empty when there is almost 4 gallons left in the tank, that is an easy fix by bending the float arm, so 1/2 = exactly 3 gallons in the tank.

I sold my 1200 20 years ago, can't remember anything about the tank shape.

[bellboy40]

It looks to me like the 1200 sender measures 101-110 ohms at empty and the 1500 measures 90-100 ohms at empty. I don't know how much difference that would make on the gauge.

Fuel sender 1200

Fuel sender 1500

[oldmopars]

Hey, thank you for that. That seems close enough for me for now. I may just use it and run the send through its stroke out of the tank and see where it ends up both full and empty. Then at least I will know and maybe even put a little mark on the gauge face before I install it.

[AZgl1800]

if you can reach the sender while it is in the tank, bend the float arm so that 1/2 tank is exactly 50% of the tank's capacity.

for the 1500s, it is very easy to do, the float is in the forward, left side position, and goes up/dn.

drain the tank, refill with 3.0 gallons of gas, and then move the float arm up/dn to get a sense of where it "should be".... and bend the float arm.

works perfectly.

Side effect: it will stay on FULL for 100+ miles, but then it comes down fast.
1/2 = 3.0 gallons
1/4 = 1.5 gallons
Empty means fumes

[oldmopars]

I think I can make that work. Thank you.
I am building a Hybrid 1200. It is a 1200 frame and engine, but has 1500 complete front end and a 1500 final/wheel/tire. No fairings, completely naked. Because it was an Aspencade it had the digital dash. So, I am using parts of the 1500 dash on the 1200. I only want the Speedo, gas gauge and the temp gauge. I will be building a custom box to put it all in.
I think I can use the 1200 sender and use the 1500 gauge, adjust it and be happy, happy, happy.
When I get the bike to a more presentable state, I will post pictures, right now it is a bit of an abomination.