Courtesy of Gearbox Mans web site.
An excellent Excel spreadsheet that works out your top speed.

This is the info given for my details.
It was my car that hit the Rev limiter in 5th.


Step 1: find out your tyre's rolling radius
(if you already know this value, skip this step and enter it below)
Enter these details:
Width (mm) 205mm
Profile (%) 50%
Rim size (inch) 15inches
Rolling radius (feet) 6.04feet

Step 2: gear ratios
(leave un-used gears blank)
1st 2.915 :1
2nd 1.932 :1
3rd 1.323 :1
4th 1 :1
5th 0.8 :1
6th :1
7th :1
Final: 3.64 :1

Step 3: shift RPM

shift point: 7250 RPM

rev drop speed MPH
1st to 2nd 2361 45
2nd to 3rd 2207 68
3rd to 4th 1709 100
4th to 5th 1400 132
5th top speed 165