I installed smart tabs on my 170 SP TL (60 ETEC) and it made all the difference in hole shot and fuel economy. Jumping from one spot to another on the lake can be a gas guzzler. I initially installed them as per Lakealbanel's but quickly realized that I didn't need them deployed when I had more than 2 people (or weight difference) in the boat, maybe because my body weight is so far back in the boat (tiller model). I purchased the PR500 locking system and am very happy. http://nauticusinc.com/products/
.....A quick note to Lakealbanel..I would suggest speaking to the installer of your tabs to ensure that he/she used the suggested Sudbury Rule Sealant as nothing else will seal correctly. There are very few locations in Canada to purchase it so if you need some (regular Maint) message me and I will give you the location details.