If you are planning on using an IO 540 out of a Piper Aztec keep in mind the manifold pressure tap is on the number 6 cylinder (this the left rear cylinder from the pilots view) whereas Van's has used a tap off of the number 5 cylinder (right rear.) I mention this as a heads up to make sure the old pressure tap off the number 6 cylinder gets properly plugged, otherwise that cylinder would run really lean if at all!
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhJwm5wNsCxx45BDZcsmWWQ9L3YFVNSrop4kuTJiD0yGwClTc33ihO9ILLuRddPtlUPDrXKPG6qZpuOPU9TMJsNKxQgoumbtitag7L0lcZQQMDzCMxYvQRA040LNvc0BiHoF6NpzRiTb2I/s320/Manfold+6.JPG)
In the first picture you can see the number 6 cylinder with a new plug installed with fuel lube and torqued to the correct setting.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjwrOhQq6HDt902t0_SYXdD4gSemLkju2vxhik1M_2UOzUudRTVWtAVCIbT7JRsMk-nimFtTgENP4Ovw0Ipg2k9R9wz4zBG6bKn1Zt5iZnJBZQml0spQ-AXwEAUvqVtDRm6fFBkYxO9vlU/s320/Manfold+5.+5)
The second picture shows the newly installed manifold tap as used on the RV 10 aircraft.