Fitting E7 in a R model

[Steve L]

I wish to replace my E6 in a R model with a E7 400 

does anyone know if a E6 timing cover will fit a mechanical E7 so I can use the existing R front engine mount. I’m fairly sure the covers are interchangeable but what about the crank pulley as I’ll need to use a E6 damper and pulley, Pictures of each crank front boss look the same but I can’t find actual dimensions. Waste or time asking Volvo. 

[JoeH]

I'd be surprised if they are the same, but then again the oil pans use the same gasket.... Get VIN numbers from an E6 truck and an E7 truck, ask your dealer for the part number for each timing cover gasket.  Same for the front main seal.  The E7 can run the steering pump on the front of the timing cover, so I'm sure the covers are different.

I'd just sift through a Mack junk yard and find a donor front engine mount.  Don't know where you live, but Coopersburg PA has a good one at the Kenworth dealership.

[Steve L]

I plan to keep the steering pump on back of the compressor. Not sure if a front mount pump will fit an Aussie truck as the steering box is right there. I’ll get a steel E6 timing cover and see if it fits. My main concern is the diameter of the cranks where the damper adapter presses on, hopefully they are both the same. If so I’m sure a front engine mount swap is doable. 

[Vladislav]

The front cover attachment (and the gasket) is the same. But actual covers may have differences. Depending on E7 modification there could be additional drillings or vice versa. I looked at photos of alu front covers removed from Renault Magnums with E7 (can't state the style of pump they had but doubly mechanical) and the covers seemed very similar to my alu E6 one but different. For example there was different fitment (or location) of the zero angle flag to set the crank. I'm sure I could use E7 front cover with some modifying if have no other options and have an original item for reference.

Also there were different styles of E6 covers. They were steel and alu and also lower bolt holes were the same OD as upper ones on some engines and some had them thicker with larger threads in the block and corresponding holes in the cover. Those are exactly the bolts to attach the front mount you're figuring about. The front crank seal of E6 and E7 engines is different. Not ready to tell right now but IIRC that's about its ID. So the cranck hub must (or could) be different. Also I saw covers where the seal was pressed straight in the cover or there was removable flange you fit the seal in and than attach it to the cover body by 6 bolts. The seals ODs were different in that case.

All in all it seems to me the swap you're going towards can be done and relatively easy. Just paying attention to every step and locating or remachining parts which wouldn't suit.