I recently completed a 416 build. Planning on firing the motor in the next 60 days.

I did not use a kit and if I had to do it over again, I may explore this avenue more so than the route I went. In any event, are you in the position to have your block and machine work done prior to making your stroker purchase? If so, this may help to answer or eliminate some choices that you are pondering.

From my experience, you may spend more in the higher price for parts for instance but then save more $$ by having to do less machining. Another consideration IMO is whether you want to go with an internally or externally balanced motor. Again, this may impact your budget, choices as to what to purchase and help to answer the question that you ask.

There is a wealth of knowledge and experience from those who have built and own these stroker motors and you are on the right track by seeking the advice from others as you go. Good luck as you proceed with all of the considerations and decisions that you will be encountering with your build. I'm sure it will be a screamer once it's done.