Hi sgetty
You could go early Type 3 rears if you want to stay wide 5, they are much bigger than stock bug brakes.
Your transmission has
1st 3.6
2nd 1.88
3rd 1.23
4th .79
and 4.43:1 diff
So at 5,000 rpm with a 600mm (used this size as an example) tyre
1st 35kph
2nd 68
3rd 104
4th 162
Early Type 3 transmission has
1st 3.8
2nd 2.06
3rd 1.32
4th .89
and 4.125 diff
So at 5,000 rpm with a 600mm (used this size as an example) tyre
1st 36kph
2nd 67
3rd 104
4th 154
Early Type 3 & 1500 bug transmissions can be fitted to your car, but they have long axles, these look a bit dorky on early models.
I'm too tired to work out other ratio options but you can plug your ratios into this page
http://www.albinsgear.com.au/ratiocalc.html
Steve