Don't know what kind of power you're looking for. On my friend's 261 we put on dual Holley-Weber two bbl. progressives, which gives him great low end power. With a full race cam, he got the idle down to about 550 rpm. I love it, he thinks he can do a little better on the top end with a 500+ cfm 4 bbl. Horsepower is over 250, engine will turn over 6,000 rpm, and it will burn the tires into 4th gear.

Here's a picture.
http://www.myoldtruck.com/gallery/files/2/3/8/Engineleft.jpg


Fred
52 3600
69 C-10