Another great service SQ offer is custom water routing kits for the 4age 20v. Whilst I was there I picked up a rear water bypass unit. The unit replaces the rear thermostat housing. The bypass was tapped to suit the standard 20v water temp sensor and a 1/8 NPT fitting for my Autometer temp sensor. As you can see the plate is shaped to match the back of the head. It has a nice polished finish to it as well, unfortunately you can’t see it in these photos due to my rather grubby fingerprints all over it. On the other side there is a channel milled to allow the flow of water uninterrupted around the back of the head.

And I also got a blanking plate for the rear water outlet.

At this stage I am not sure what I will do for the thermostat and the front water outlet from the block. There are some good reports of using a Yager branded outlet which includes the thermostat in the outlet. But I may look to mate the front half of the 20v water pump with the back of a 4AGE RWD pump. This does work out quite nicely as the RWD pump has the thermostat built in. However there is a modification required to shave down the height of the impeller blades of the 20v pump. I do have a concern with doing this as it may affect the pumps flow capacity. This setup would give a near factory finish.