There are several issues with using 1/8th scale diff parts.
The holes for the diff mounts may not line up correctly and since a 1/8th scale diff is longer, you would have to drill new holes in the front and/or rear to attach the 1/8th scale mounts. This would also cause you to have to use different size dogbones.
The output yokes are smaller bore and depth on the crt.5 so std 1/8th scale yokes are not compatible for this application. You could change to 1/8th scale yokes and dogbones on the F/R but these parts are heavier and really overkill for 1/10th scale trucks.
The crt.5 uses 10x15mm bearings so any combination of 1/8th and 1/12 scale parts won't be compatible.
So far there is no easy solution, until now

Well, almost now.....
I received some stuff for other projects today but nothing for this solution

Hopfully it comes later this week.
This solution should be drop in and go...
Once it arrives I'll have an update shortly after