You sound pumped! Weld both slots on the outside & the dimention for how much slot length you need is in the archives but it ain't dead on accurate so go a bit shorter then elongate the slot(s) with a rattail file as you tune it to get it fine tuned (keep both sides equal). If you are using (1) spring it can go on either side & if (2) springs it does not matter which side which one goes on as the cam plate always advances in a linear fashion (the elongated loop spring that you toss is an exception). You'd want to weld the inside of the slots if you were using a non Mopar (longer) spring(s) otherwise the assy (with that) would flop till the weights moved out & the slack was taken up