First of all, the pin, needle bearing and rod are of low quality. Secondly, we tend to put a huge load on them as we "hotrod"our engines by increasing compression and rpm. Third, we tend to low amounts of low quality oils so the the pin runs hot and suffers metal fatigue.
If you (1) use a better quality pin and bearing from the beginning (too late for that rod), (2) a good oil like Maxima 927 Castor oil at 32:1 and (3) keep the compression ratios reasonable your pin (and piston and cylinder) will last a long, long time. I know this from my own experience.
Those are some wild looking transfer ports, how do they work?