A comp cams 294S is a real good cam to use with a street tunnel ram. Needs around 10:1 cr. Needs a 3500stall converter and some gear. I"d pass on the 12:1 compression idea. You'll get real tired of buying race gas for the street. Needs a modified distributor advance curve.
Add a pair of 450 to 500cfm carbs and it will perform very well and drive nice on the street. A tunnel ram will need a longer warm up period to get the some heat in the manifold plenum for good drivability but once warmed up will run and drive fine.