The true speed of Delta 3200 is around ISO1000 (800-ish for T-max P3200 btw), so no matter what you do, you basically push-process those films unless shot at ISO800 or slower (why would we do that, right?). In other words, it doesn't really matter.
Just be mindful of fact that the faster the film, the quicker it deteriorates after expiration, unless kept cold.
Hello Baachitraka
Here are a couple I shot with expired 3200 as old or older than yours that I shot at 1600, I have a bunch more of the film but do not care for the look, except for the birds on the pole.
1250 is the speed at which I regularly do shoot it. In my case this is 120 roll but I can see no reason why using 35mm should be any different.I develop in Xtol 1+1 for 19 mins at 20 degrees C. The time is based on John Hick's time in the Unblinkingeye site which is 12 minutes at 24C. At 20C the correction is actually closer to 17 mins but I found that an extra couple of minutes is better
The true speed of Delta 3200 is around ISO1000 (800-ish for T-max P3200 btw), so no matter what you do, you basically push-process those films unless shot at ISO800 or slower (why would we do that, right?). In other words, it doesn't really matter.