Good afternoon,

I plan on opening a doorway from 32" to possibly 48" opening if I nail 2 2x10's together sandwiched with a piece of plywood, or OSB would that allow me the span support, or is that not enough, or overkill. From my days calculating and building I say yes that should
do it, possibly using 2x8 would probably do it but what is your opinion?

Really depends on the static load above the doorway. What size header is there now? If there is 2x8 there now, and the load above is minimal, then a 2x8 should be adequate. If the load is more than minimal, then oversizing the header to 2x10 may be in order.

I asked that this question get copied over at Construction forum, to perhaps get a better answer.

Yes that is fine, make sure you have jack studs under each side, but other than that its good