What is the fixed income allocation in your AA?
If it is significantly greater than what you would contribute to the plan (and what it would grow into), I would consider some portion of my fixed income allocation as part of this plan.
I wouldn't make the plan anywhere near my entire fixed income AA simply because #1) it is not liquid, and #2) if 30 year treasuries yield greater than 5% in the future, the pension will underperform*. IMHO, you'll want to have a significant portion of your fixed income in liquid assets so they can serve an appropriate re-balancing function during large swings in the market.
If you do have a fixed income allocation already, you could shift a portion of that AA into this pension, over time, and free up some cash to put into equities in your other accounts.
* Your OP didn't specifically state whether the pension was capped at a maximum 5%, or whether that was a minimum yield. My remarks assume 5% is the maximum yield.