OT I would suggest you finalize the initial with the vacuum gauge method then with that number in hand shorten the slots to get 38 total (initial+slots with can capped) then play with springs & mix and match any combo so that you are just under the pinging point at WOT up thru the gears on your hottest/driest day & no matter what RPM this makes the slots max out at. Use a pair of needle nose pliers to expand the clip to the point where it will come right up & out. lastly plug in/adj the can (if used) staying just under the pinging point in everyday driving under varying load/rpm conditions on your hottest/driest day & CCWmakes it come in later. On the springs you would wanna toss the heavy one with the elongated loop on one end. MP and mr gasket have kits of light ones