Any gains adding 1.6 rockers to stock 273?

With 85k on the clock. I would verify that the original timing set has been replaced.
If it is not 185k there is a chance the original set is still hanging in there. The nylon teeth would have to be very brittle by now.
I put a street master intake and AFB carb on a stock 273 with manifolds and dual exhaust. Seemed to make a worth while difference.