If you are wanting to switch the four to a five speed I would recommend going
with the New South African five speeds with the .457 ring and pinion.  They
cost a little more but are worth the money (IMHO).

While the gearing is similar than the .483 or the .543 diesel. the use of the
.457 ring and pinion makes a world of difference.

The fifth gear is like a true overdrive, it cuts the RPMs by @800 RPMs.
Fourth gear can go from @20~25 to @70, fifth goes from ~35-40 to 80+.

The gear pattern is better matched to the power curve of the Wasserboxer
engine or any of the other types of moderately HP engine (under or @ 150 HP,
any more and the tranny will need to be beefed up to keep from breaking
trannys$$$)

The oil fill hole has been relocated to in front of the shift rod mount.
Made changing the oil REAL EASY and I mean easy no more contortions to get
the oil in the case...

There is NO modification necessary to the shift mechanism except that the
front mount needs to be shortened @1.5 inches (Weddle would know EXACT
amount) the rest bolt up (It did on my 88)

Some winter benefits discovered during my drive in the snow and ice: Having
the reverse and first on the same plane, shifter pressed, enabled me to shift
between first and reverse rapidly getting me unstuck several times.

I am used to having to press down the shifter to go into first, shifting into
second has become second nature.  Once in a while I will miss second, but
that is getting rare now, other gears shift fine.

I am running 205x70x14" tires, so if your tires are smaller the engine will
rev a little higher...

The SA tranny (as compared to the used or older rebuilt five speeds) has the
hub that was redesigned to handle the extra weight, plus they include the HD
parts VW added.

Ratios are similar to the five speed diesel except that the R&P is .457 not
.543.

1st      4.111
2nd     2.333
3rd      1.476
4th      1.023
5th      0.816  some diesels had a .77 fifth gear
Revers  3.667
Transaxle 4.571

Robert

Standard disclaimer:
"I have no claim in the business other than a satisfied customer"

(Weddle rebuilds the New SA trannys because they honor the two year warranty
and to make sure all is right inside the tranny before you get it.)

Weddle can be reached:

Weddle Engineering
Billing: Weddle Engineering P.O. BOX 1075 Goleta, CA 93116
Shipping: Weddle Engineering 700 Becknell Road, Unit A Goleta, CA 93117
Phone: 805-696-9665    Fax: 805-696-9667
Contact- Chris Weddle
http://www.2weddle.com