Since I was never really happy with that one disclosure about J-10's range, stating 1650 km for "Basic range", here's the result of my analysis, flawed as it may be.
Using photographs of J-10 and F-16, and known values such as missile lengths for comparison, i got the following dimensions for J-10s drop tanks:
Big ones: 5.98 meters long, 0.65 m in diameter.
Centerline: 4.57 m long, 0.58 m in diameter.
Sizing them to F-16's tanks and their known quantities, adjusting for shape difference, I got the following fuel hold approximations:
Big ones: 1670 liters (440 gallons)
Centerline: 900 liters (240 gallons)
That would suggest drop tank hold of 3520 kg, compared to USAF F-16 of 3267 kg.
Internal fuel hold is, sadly, unknown. So i used other similar aircraft to approximate it. F16 holds 3200 kg, M2000 holds 3300 kg (similar because of the delta wing?), Gripen E holds 3400 kg.
Conservatively, I approximated 3200 kg for J-10's internal fuel hold.
Then I used ferry ranges of those planes, their total fuel holds and fuel consumption of their planes. Luckily, fuel consumption for Al-31 is known. Using all that, I approximated that if F-16C uses 1.86 kg of fuel for every km it crosses, J-10 should use between 1.9 and 2 kg for every km it crosses. Which finally brought me to final ferry range estimate of J-10A: between 3350 and 3550 km. I am probably wrong, of course, as this is just a crude analysis, but I think I am not more than 5-10% off.
