Starting level for 4k/8k Norton pyramiding after 1k

I just purchased a 220/1000 Norton to impart a new bevel on a problem W&B eBay special. I started with the 1000 and obtained a nice bevel which passed the TNT rather quickly along the whole bevel and resulted in a sharp but fairly rough edge. Now on to the NOrton 4k/8k combo. Looking at the WIKI for pyramiding, there are 8 rows which start out at 25 4k / 25 8k and end with 1 4k and 5 8k. What's a good starting point on the 8 level pyramid?

What I usually do is after I pass the TNT on the 1k I do 10 more light x strokes each way on the 1k. Then start tye 4/8 at 25 and follow the chart. You can start at 15 and see how you end up and repeat if necessary but it depends on the razor. No more TNT as you probably know. Just TPT and arm hair if you want to and have any left. :)

Thank you. I think I'll start at 25 as I have plenty of spine left.