I’m well along on my engine rebuild for the Mk10 and also far long on the transmission conversion to GM700r4. A complication arises about the sump. The Mk10 external oil return fouls the GM starter. I had though I could modify the return tube, but as I fit things up, there is not enough clearance. Possible solutions include modifying the Mk10 sump or using a different one. I have a parts engine from a 3.8S that has the oil return angling into the front of the right side sump “ear” rather than at the top, and I think it will work as far as starter clearance. John’s Cars kit does work for these with a change in the oil filter housing from angled to vertical style.
I think the oil sumps are interchangable between 3.8 and 4.2 blocks. Can anyone verify this to be true? I think the pickup tubes are probably the same. If nobody knows for certain, I’ll have to pull that sump, and I hate to break it down just to find out.