650 dp vs 750 dp in a 408
Every smallblock i have ever raced has always gone faster swapping to a bigger carb. This asumes they are tuned correctly.
The only time the gain was meager was going from a trick 1025rs Race Demon to a pro systems 1100 Dominator.
Even the enginemasters 318 i raced that went mid 11’s in a 3400 pound car was a tenth quicker with a 950 than a well sorted 750.
Never say never, but i can say i have never seen smaller ET better. Ever.