Recently I picked up a 6.7 to investigate, curiousity, ya' know?
The intent is to investigate, then possibly put a VE pump on it, the following is what I have noted so far:
1.Contrary to popular belief and as some have stated, they
ARE NOT "just a couple bolt holes and a dowel pin off".
It's more like 7 bolt holes, plus BOTH dowel pins are WAY off.
Then there would be the filling of old holes that are half-off and re-tapping them slightly over from the original holes.
There are more than enough bolt holes in their correct places to hold it stable enough to do measuring and tracing to get the missing/wrong holes corrected and added in.
2.The cam timing pin housing located on the back of the VE case WILL NOT clear without relieving the block of some of the extra casting there. It is "minor surgery" with a grinder to correct this and it affects nothing else.
The simplest solution is to relieve the block to bolt it in, welding up the holes for it would be more work, IMO.
3.With the VE pump set in place on the bolted on case, I found that there is a bolt boss on the block that's not necessary for anything related to VE, BUT it interferes unless the VE is set at full advanced. This block bolt boss could be removed.
The part that hits on the PUMP is one of the 2 un-used mounting bolt holes between the head and the advance rib on the pump. This could theroetically be removed, as well.
4.Geartrain gears. Commonrails use straight cut gears. VE, P-7100 and VPs all use helix, or diagonal cut gears, so the crank gear needs swapped, as well as the oil pump and cam gear.
5. Oil pan rail. The bolt pattern is totally different at the front because of the timing case depth.
So far it looks like the pan's whole bolt pattern is also slightly different, but I have yet to trial fit an older pan on it.
6.Crankcase venting. The commonrail blocks do not have a tappet cover, rather they have cup plugs in the side of the block, in front of each lifter, to allow the lifters to be held up. This in itself is no problem, but the crankcase vent hides right where the traditional vacuum/power steering set-up is located. The vent resembles a fuel pump block off plate with a hose barb affixed to it.
My preliminary idea on this is to fully block it off and vent from a place on the valve cover.
The revised vent block-off would incorporate a system for mounting the rear of the injection pump and the power steering/vacuum pump rear support.
All in all, as it stands, it appears the VE conversion (or P-pump, for that matter) could be done with a fairly minimal amount of specialized machine work and it's likely it's not beyond a person with a good grasp of how to drill and tap straight holes.
The most critical thing is getting the case properly aligned to allow proper cam-to-pump gear meshing, then placing the dowel pins properly.
That can be done by finding the proper mesh depth on an already assembled VE engine, along with straightedges at the panrail-to-timing case area.
Mark.