Sandy,
I suggested 6,000 RPM because I knew it would be a fresh engine, and twisting it past that is not good until you have some time on it.
I have a 289 in my GT350. It has a mechanical driven cable tack, with a tattle tail. The guy I bought it from worked in the machine shop where I got my Cobra engine done. Well know history with the shop and the machinist. Paul set the car up to do drag racing, with 4.86 gears. I thought that would be the first thing I would change, but I just left them in there. I have seen 8600 RPM in 1st, 2nd, and 3rd gears. Comes out of the hole like it is shot out of a cannon. Great fun. I have 3.92s with a 27" tall tire on the Cobra, and have taken it up to 7500 RPM in 4th gear = 155 MPH.
I am, as everyone here, interested in your build progress, and the stats to the engine/trans/final gear ratio, ect. I wish I was in your shoes, and looking forward to having you post more information as you go forward.
One last thing.......Dang, that is one great looking car!!!!!!!!!!