Get the timing adjuster if you don't plan on buying a chip. I would save the money and get a dyno-tuned chip. Even if the car is very mildly modded. By doing this you will not need to buy a timing adjuster, a speedo recal, mil eliminators, plus the gains. I think I paid $500 for my diablo flip chip and 2 hours on the dyno.
Ok you get a dyno tuned chip $350~ish and your timeing is set to 15*
summer time come and 15 is just alittle to much or your short on money to get Premium gas.. well your stuck with 15 unless you pay for a reburn..
Get the timing adjuster and you can make your own changes.. cars pinging take it down 1* and so on..
Ya right now I only have it installed, my pullies are on delievery and I felt some nice low end power set at 16 on 93.. and if gas prices become 3 dollars like some people are sayin then u can always lower it back to 10
I thought they were worth it. Definately a SOTP difference. But I put in pulleys and the T/A at the same time, both Stedda. Mine is set to 14. I could probably go higher cause I always use 93 octane, but I'm happy with 14 for now.