Recess in firewall
IF you have an older RV-6, then it might not have the governor recess in the firewall. It can be installed but it's a job and you will have to remove the engine and engine mount to accomplish this task. Also, if the builder routed anything through the firewall in this area, you will have to move it to another location. The installation of a constant speed takes several things
1: Getting a recess in the firewall and the installation of the prop governor and drive.
2: Getting the correct oil line from the governor pad up to the front of the engine and attach it to the oil boss on the right side of the front case.
3: Modify your baffling to allow the oil line to pass through it.
4: Remove the front plug in your crankshaft and make sure you have the oil tube in your crankshaft. You need to make sure the back plug does not have a hole punched in it so the oil does bleed out. This is done on fixed pitched engines so the oil has somewhere to go.
5: Install the correct prop governor cable and bracket on the governor.
6: When you install your prop, you have to make sure your spacing on your spinner to cowl is correct. Some people with the older cowls will have to get a spacer from Saber Mtg. to make it fit correct.
7: You will have to make a new spinner because it mounts differently than a fixed pitch prop. Also the hole cut outs for the blades need to account for full movement of the blades from fine pitch to coarse.
8: Weight and balance will need to be redone as the constant speed adds about 20-25 lbs in weight, unless you get a MTV prop or Whirlwind, then maybe only 10-15lbs.
Hope this helps you out...