I would suggest you read this thread:
https://forums.maxperformanceinc.com...ight=Dual+quad
As stated in the thread multiple carbs are not cumulative. In other words, 2 450cfm carbs are not the same as 1 900cfm carb. Do your research before settling on carbs that are too small. Tom S and 61-63 are both very knowledgeable on this subject. 61-63 has built SD clones for years and knows them like nobody.
Good luck