might want to be careful brench mounting this engine or any engine i herd mounts could break.if you think about it the bence dosent absorb mutch shock.i just waited&ran it in the plane to be safe.as far as the prop goes 22x8 for break in.as far as the oil goes any mineral oil should do.i think both your props might load the ingine a bit mutch for break in.i just used a cheap 22x8 zinger fro break in.you dont want to let her get to hot the zinger will really let her rev with out mutch load