self directed 401K, LLC

I am trying to set up self directed 401K, LLC with check book power for myself and my wife. My plan is to use combined cash to purchase a rental property. I have consulted with an escrow company. It seems to be a workable approach. We can close the escrow by writing two checks from me and from my wife (e.g. 100K each). However, I am not sure how to return the annual profit or gain (when we sell the property) to the IRA. Should we split the profit first according to the ratio of investment and then return to each IRA? What is the rule? Anybody has experience?
Thanks!