318 2bbl manifold swap with OE cam - worth it?

Now would be a good time to ask... How many of you will admit that you bolted a bunch of easy to do performance stuff on a high milage engine ( over 70K ) , only to have the bottom end come apart in less than 20K more miles ?
My suggestion would be leave the hood closed and stay off the track until you have a complete fresh engine to bolt performance goodies on.

Everytime I ever tried bolt-ons, was either the bottom end or the valve train that let go.