@BrianG
the frame with centerdiff weigths 492 grams, it sounds havy??

indeed, the back wil have a kick down
@JThiessen
I measured everything with a caliper.
I don't know de excact distance from the holes of the top to the holes on the bottem.
al the screws will be countersinking, but thats for later.
@david lamontagn
for the rear center drive shaft I use a shaft that usualy goes from the front/rear diff to the whiel.
ps. thanks for al the comments so far!!