I removed the stock heat sink paste from the Intel cooler and used a dab of artic silver instead. The actual swap was painless. Turn the little clickers counterclockwise and out comes the cooler used with the SB - push click and the cooler (same) with the IB dabbed with artic silver is installed. Had been using two 4gig memory sticks and decided to add two 2 gig sticks that were collecting dust in the closet.
Feeling optimistic I closed up the case, attached power and other stuff and hit the start switch. It fired up, died, paused a few seconds and fired up on its own again. Good I said, now just type in my win7 password and we are off and running (by the way, the video off the DH67BL motherboard had fallen back to basic numbers for resolution, probably because of the switch in CPU video capability, SB 2500 to IB 4000). But, but, those passwords must be known by the processor because the machine failed to recognize the password.
After a number of tries I took off for supper anticipating having to reset CMOS because I didn't have a password reset disc. About two hours later I came back upstairs and the machine had on its own resolved its issues with the new CPU and worked as usual, password and resolution as before. Don't ask me how it did that upstairs all by itself.
As an assurance, I reinstalled all of the motherboard drivers, and now it is working like a CHARM