trailing arms
 

will vw trailing arms fit a T5 356B?

if not any idea how to put VW running gear on a 356b

The axle tubes ends are different on a 356- the shock mounts in a different place and at a different angle on those cars- and the trailing arms are very similar dimensions but not exactly the same.
The 356 Used the VW split case (pre 59') Differential- in many cases the metal pieces in the trans were hardened to different specs- there are painted stripes on the actual axles that correspond to different heat tempering (or maybe even nitriding?).
The moral: you CANT bolt a VW tranny into a 356B without more $$ in adapting the car to the tranny than would cost you to just buy a rebuilt 356 tranny outright. Some of the parts can be swapped, but as for the trans ONLY the differential and actual axle tubes and axles (not the cast axle tube ends ends) is an exact swap- and even then there are minor differences.
-Bob O

Another neat tip: the difference in the cast axle tube end (shock mount) will prevent many cool VW aftermarket wheels from bolting onto the 356 smoothly- sometimes you must use spacers...don't ask me how I know.