750 Holley or 650 Holley DP carb for 340-4 speed?

I have had both Holley 650 and 750 DP on my 69 340 4 gear swinger with 3:55s. I always end up with the 750 back on there. Seems to give it a little more top end. The 650 was nice and crisp as well. Either is a good choice. If you are going to race it Id go 750