I'm wanting to switch to wood for shooting through my pronghorn, 47#@28, my draw length is 29.5. Should I go with 50/55's cut to around 30.5?

I am not sure of the centershot measurement of the pronghorns, but I would guess you are going to be underspined with 50/55's.  You are likely pulling just over 50#'s @29.5".  I would guess 65/70's.  You might get away with a 60/65 if you are shooting 125gr pt., or you may need a little more if you are using a heavier point.  You might try one of the test kits with multiple spines, or I sometimes will buy towards the higher end and sand the middle 1/3 of the shaft a little at a time to experiment with different spine.  Of course you will need a spine tester to do that.  If you are going to shoot woods seriously, you will be better off buying or making a spine tester.  Careful, wood arrows are addicting!

My Pronghorn is 56# @28", and I'm drawing about 29". I'm shooting 65-70 with 30" arrows tipped with 250 grains up front, glove release. When I do my part, they fly like darts and hit with authority.

I shoot a 51#@28 Pronghorn at 29.5" with a 70/75 30" arrow, 160gr head and they fly great. I would not go under 60/65 even shooting 125gr heads and would recommend 65/70.

47, you are shooting about 51-53 lb and will need to add 10-15 lb for the added arrow length over 28".  65-69 sounds about right to me, too.  My Pronghorn is 54 lb at my 26" and paper tunes a hole with a 28", 70 lb spine and 240 gr total up front.  If you plan to shoot with a bow quiver, install and fill it when testing your arrows.

I'll send a PM.

I was wanting to shoot 125 up front to have a lighter arrow for 3-5/target shooting. In that case it looks like 60/65 with a 30" arrow would be about right. I called up Herb and that's what he recommended a few minutes ago. I cheated  :D .

I own two 62" Pronghorn takedowns.  At my draw, one is about 52.5 lb's and the second is 54 lb.'s.  In a cedar shaft I typically shoot compressed/tapered 65-70's with 160 grain point.  If I were to shoot a lighter weight point or parallel shafts, I'd drop down to 60-65's.

no cheating there, 47.  That is the best place to go; Herb is gonna know better than anyone.