It is physically impossible to run an engine without the pin!! You may as well take out the piston and only use the connecting rod!
You could use the whole lot without the retainers/c-clips, but you risk a certainty of the pin moving sideways and ruining the sleeve.
If possible, give it to somebody that knows what they are doing, and let them reassemble/disassemble the engine so you know for sure nothing will go wrong! Id say send it to me, but I live a looooong way away from you!
Car-less (Velox V10 or 733) // RB T10.5"+" (JB Modified) // Bluebird BMS-990DMG (St) & BMS-631 (T/B) // ATS 16% // Capricorn Wheels // Protoform
"70% of the time, it works ALL the time"