Will I get any more "noticable" performance/HP from going from a 671 to 871 blower on a 530cu/in engine?

Yes, especially hot hot weather and altitude.

- and you can usually underdrive a deal like this a bit as well easing some load.

The air that does get delievered will be cooler at given rpm as well.

UD

Depends on which models your swaping out also....but yes, the 8-71 will labor less at a given boost load than a 6-71 more so on a large cube motor.

I had a 460ci in my scarab,debated over the 6 and 8 ,I was told to go 10/71 I regret it now!!!!

Now I am limited by the 8 71.ital only make so much power