Checking the number of turns between the wheel and the driveshaft can be misleading.
First of all, the driveshaft should turn 3-1/2 turns while the wheels turn once. Not the other way around. But this will only be true with a limited slip differential! (Posi.)
If the rear end is an "open" style differential, one wheel will turn twice as many times as the gear ratio, while the other does not turn.
The best way to check an open (non-posi) gear ratio is to jack up ONE wheel of the car, put the transmission in neutral and turn the raised wheel through TWO revolutions while counting the number of revolutions of the drive shaft. (This is a lot easier with a helper.)
If the driveshaft goes through 3-1/2 revolutions, then you will indeed have 3.55 gears.
If you have a limited slip differential, raise both rear wheels and rotate them through one revolution while counting driveshaft turns.
