Some of you may remember that I was having an issue with the spruce I have not being long enough for the rear longerons, I called an amish lumberyard the other day and the guy says he can probably help, anyone see a problem with me scarfing white pine into spruce?

It will scarph fine, but I would try to place the scarph where the member is going to be pretty near straight.  It will be strong enough but there is bound to be a slight discontinuity in strength which in some situations might cause a stress concentration.  Practically speaking I would think you would be OK.

Tom