Ok so I bought a fully restored 65 GT Fastback. The engine is working and sounds great. The only problem was that my speedometer was off by about 15 mph and it was reving very high, 3000 when i was at 55mph. So I checked the gear ratio and it was a 3.20. I put a 3.00 in and now it revs 3000 at 70mph. It has a 3 spd automatic transmission in it. I can feel it shifting through all gears, but should it be reving this high at only 70mph in 3rd gear?