im looking at new carbs and have narrowed it down to the edelbrock thunder series 650 and 800cfm. I was looking for opinions on which one to choose the 650 or 800. My motor is a chevy 400sbc bored 30 over. Dart heads 10:1 compression edelbrock intake. thumpr cam 227/241 duration, .479/465 lift.

I have a 800 cfm on my 408 and also a 750 on my 400
And they both work good. I would think a 650 is on the small side.

A hotted up 400 small block will take the bigger carb no problem. Vacuum secondary carbs are "self-sizing" to a great extent anyway. Almost impossible to over-carburate.

Thanks for the responses guys. I will get the 800cfm.