[irienz]

I asked this group much the same question in 2007. Here is the summary of the answers that I posted then:

"Thanks to all those who replied to my initial post.

"The most frequent recommendation for a replacement carb for a 411 was an Edelbrock usually a 600 cfm model, although others had 650 and 800 cfm models. Almost everyone refers to greatly improved fuel consumption, up from 13 mpg to 20 mpg or so.

"The Edelbrocks are modern copies of the Carter AFB. That brings me to a question: do these carbs experience the fuel boiling problems which lead to the introduction of the Thermoquad (and some 411 owners to convert to fuel injection)? This is usually worse in a Bristol V8 , because of the cramped underbonnet area compared to a US V8. Is a 411 with an Edelbrock hard to start when run to full temperature and then left sitting for a few minutes?This is a specific reservation which my mechanic has about these carbs, both generally and especially in a 411.

"The other recommendation was for a Holley 4 barrel. Clyde recommended a 750 cfm pumper. My mechanic likes the Holley Street Avenger range and thinks the 670 cfm would be best."

I proceeded to replace what had been a bolt-on aftermarket injection system, with the Holley Street Avenger 670 cfm with electric choke. It has worked superbly and I have no regrets. My car has Edelbrock alloy heads and inlet manifold, high comp pistons, a modified camshaft and slightly larger diameter exhaust. I would not use a higher flowing carb and a 600 cfm should suit a standard engine best.

Generally the feedback at the time from those who used the Edelbrock replacement was also very positive as well. I think either woudl be a safe choice.

Chris Browne