Installing Rallye Dash in a '74 duster issues

I wanna say that using the brake-lite indicator is all messed up. Firstly you will have to be an electronic genius to still keep the proper function of that light. And next, you will not see that light way down there in the darkness of that behind the steering wheel pit, and thirdly, have you seen the er.... brightness, of that red lens? I had to sand mine down to half thickness, and put the brightest 194-type bulb in there, that was listed in the catalog, to just see it to pass the safety test up here.
Naw, a better idea, I think, is to buy a tach with a built in shift-lite.At least I thought so, and that is what I did.And don't think as a streeter that you need a 16 inch 12teen thousand rpm Monster tach with 6 lites hanging off the side. As a streeter you need no tach at all. Think about it. You are geared for probably 50 mph at shift rpm in first gear. So you can just watch the speedo. With a 120 speedO,nice big numbers, easy to see, all lit up, right there front and center. Nothing tricky about that.And the needle;bonus, it is at what? 11 o'clock, or there abouts.Sweet.
But if you think you need a tach, I found the Autometer 8000, 3.5 or maybe it's a 4", job, with built-in shift lite more than adequate,lo,these many years and miles. But with an engine that willingly revs into the 7s, mostly I just shift when the exhaust pipes start to scream,lol......Lite?, I dooneedno steenkenk lite! You have to say it with a pseudo Spanish accent like that short Ugly guy in the Eastwood movie called,oddly enough; theGood,theBad,and theUgly.