Ron,
You really don't need frame blocks with a Ruger. The frame is sturdy enough. The factory doesn't even use frame blocks.
1. When removing the 1st time, Ruger barrels are very tight, don't give up! Soak barrel joint with penetrating oil.
2. You will not tweak/bend a Ruger SA frame with this method, so don't worry about that.
3. You'll need a 3 ft piece of 2x4 with one end cut the size of the cylinder window.
4. If you don't have a barrel vise, you'll need a very big vise that you can really tighten to about 150 ft lbs. That means very tight!!
5. Take two blocks of oak or other hardwood about 3" x 3" x 3/4", clamp in a vise and drill a hole a little larger than diameter of the barrel, thru the seam so you have 1/2 of a hole in each block when you separate them.
6. You will need two thick pieces of leather, 1/8" or 3/16", for padding between the barrel and wood blocks.
7. To absolutely guarantee that you don't mar the finish, spiral wrap your barrel in duct tape folded in half the long way so it's sticky on both sides. I DO NOT use rosin as some suggest, it will rub off the bluing when the barrel slips, and it will slip until you have it tight enough in the vise. And you don't find out if the barrel is clamped tight enough until you finally hear the "crack" when it breaks loose instead of slipping.
8. Clamp the barrel w/blocks & leather making sure there is no pressure on the sight; you can pop it right off when the barrel slips in your blocks, and it will slip until you tighten the vise 3 or 4 more times.
9. Tighten vise until the barrel won't slip in the blocks when you apply pressure on the 2x4. You'll hear a crack when the barrel finally lets go. I always pre-soak with a good penetrant.