Saving Old Seagulls

Looking back through all the posts on fuel ratios, I've decided to run my forty plus on 10:1 with the needle set to top of slide barrel. Since I run a 102, it would make sense to have only one mix of fuel supply. On the engine identified page my forty is shown as exact date unknown (FP215R5) with the later forties shown as 25:1 ratio. My question is; with the correct needle, does it matter which mix I use?
The 10:1 would be better for the engine. Thanks guys.

Forgot to add to the last post..... Are there any references to the water flow rate coming out of a TC 102; say, at half revs? Or is it enough to feel the temperature of the water and judge the rate to be adequate?