Edelbrock offers a number of different heads for the BB. They have a rect port model with 118cc chambers(60559). They have an oval port in 110cc(60459). The original 291 chevy steel heads were supposed to have a 109cc chamber to produce 11 to 1 comp. You should check the cc's of your factory heads first to find out what you have, you might be surprised! They might actually be bigger than specs.(credit to Mr Clary for this input)The 118cc Edelbrock head may actually give you a similar comp ratio. If you go the oval port route a diif intake would be needed. The Edelbrock heads also have a very thick deck and you can mill them for higher comp. The 110cc oval port heads with a Performer Air Gap would be a good street setup. I have this on my 68 427 nova and it runs strong. Check out the heads at
www.edelbrock.com
wilma