I did this to my 69, I bought another gage pod from ebay and then bought a tach and Speedo (5") from ebay then had to by a 2 1/8 gas gage from summit and put it in. I have under 200 into the whole thing and still have my stock gage. I will post better pics from my other computer tomorrow.
I had to do some very minor detail work to make it look good.