Anyone have any experience with Aluminium radiators over stock? I know I have a stock 4 core radiator now that is shot but don't know if the 2 core Aluminum radiators are worth the investment?

I replaced my orginal with a aluminum radiator from Classic Industries. Car was running 220 to 230 in the Phoenix summers even without the air on. Even with lower thermo. Tested electric pusher fan along with normal fan. Still was over heating.
Put the Aluminum raditor in with a 192 degree thermo and problem solved.

Condition is more important than material. A clean (inside) original works just fine.
Question is: what problem are you fixing?

excactly ,you could run an old clogged aluminum one and replace with an 'original' and getting great results too...

Aluminum is lighter....

yes....and on a +_ 3500 lbs car with 250- 350 hp, it will make a HUGE difference...

I will use nothing else.

Of course the factory one for my 67 is stored away since car is 90% original.

I had my 4 core recored. the radiator shop told me that having mine redone over an aftermarket mine would be about 6 pounds heavyer meaning to me as a machinist thicker metal they did a nice job and fast

Not sure what you meant.
Original brass or aluminum being heavier.
Aluminun is way lighter.
Brass does conduct heat better.
The new design 2 row aluminum radiators are way better then 60's tech at cooling.
If you want, i will weigh my 67 original 4 row vs my rodney red raidiator when i change cams before spring.
Just remnd me cause after lifting several of each, dont even consider using orginals any more.