Marco7 I have a D-20 case Tera low kit with offset D-18 internals and Warn over drive. I broke my first over drive sending metal throughout the case. Wasting the first Tera low kit. I'm on the second now. Yes both of the damn things are annoyingly loud I have to use ear plugs on the road or will get a headache. Offroad low RPMs not as high pitch, it's bearable. I've used synthetic oil and standard gear lube no difference in tone. The Warn over drive will pop out of gear and grind gears while shifting with the synthetic. Mr Willys says not to use the synthetic oil with the brass synchro ring in the overdrive. He is right. With this set up the t-case is still offset. Bottom line I love the whining POS, just wearing ear plugs is the only fix.
'44 GPW Stretched and Linked
'51 Willys bigger Stretch bigger Links