I've got a 750 on my 289 and it runs better than it did with the 650... it all depends on how much power you plan on making. I'd say 350-400hp a 750 is probably about right, over 400hp an 850 would probably work... but like dfree383 said if you can't tune a carb, then who knows.
I have run 750 vaccum secondary with Great success on Street Strip Cars over the years. They are pretty forgiving. Even better than the old 3310's would be a Edelbrock 750, Especially if you are a beginner, They are about a simple as a performance carb gets and very forgiving.
1991 LX Mustang 347 C4 combo Mid 11's with the AC on.
1984 Mustang GT 460, Powerglide "Still putting it together" hoping for 9's !!
<font size=-1>[ This Message was edited by: dfree383 on 2/28/06 5:43am ]</font>
I just moved up to an 850 Proform from a 750 Holley HP and gained 2 tenths on my 331 without any other changes.
Don't know why, all the books say it's way too much carb for a 331, but the numbers don't lie.
What are you doing with it? Is it a race car, Street Strip or a cruiser? Everybodys perferance and ability is different, If you know what your doing the some of the race carbs would be a good choice, if your new at it the its probably better to go with a smaller more street orientated carb. If you try going with a Big Carb and you don't know what your doing you will only get frustrated and be chasing problems. The fun is in driving the cars not working on them.