Which Motor is Better

Turnigy Aerodrive SK3 - 6374-149kv Brushless Outrunner Motor ormono drive r-spec pro

or any kv on a 8s setup

At 8S I would go for around 200kv to 250kv. The Rspec is 190kv which is okay since it comes with a Keyed shaft and circlips. Check out DIY’s selection of motors. 149kv on the Sk3 would make your top speed quite low with common gear ratios.

really so 200kv to 250kv thanks becuaes my board when its working hits 20mph but i want go at lest 25mph

If you can wait a bit, I have some 6354 / 6374 190kv motors on pre-order. https://electric-skateboard.market/product/190kv-sensored-motor-6354-6374/