We are all still HARDCORE runners, and some of our combo's STILL work today. It's sort like Macy's NOT telling Gimbel's their sales profits. Combo's are well-guarded, to most, unless obsolete!! Help is one thing, since it's generic, everbody wants to run better. But to tune the SAME combo, and be better on the run than your competitor, isn't good especially if it's EXACTLY the same down to the innards!! And you are NOT racing partners either!! Not Good!! In match/class racing and NASCAR, I can see it. Maybe somebody else has a different take on this!! Food for thought!!!!
My take on it---the Web is SO large, the chances of running into someone who duplicated your combo EXACTLY & run into him are pretty slim. even if the engine was the same, the car, suspension, trans & driver are all variables that could make the engine combo a dud for a particular racer. Plus some of the parts that were run are so old maybe 10-20 percent actually have them anymore? My guess is, building my "old" stuff with today's modern technoogy & building techniques, coupled with the better parts for the rest of the car would push the same car into the high 9s/low 10s? That would translate into a3/4-1 second e.t. reduction---but since I could NEVER afford another '67 'vette, it's all a moot point. That's why I have no problem bringing this od stuff up.
In match/class racing and NASCAR, I can see it. Maybe somebody else has a different take on this!! 
Food for thought!!!!
