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

I would go with the 4779 Holley 750 Double Pumper.....but know the 750's with the 4779 stamped choke horn.....get pricey.

In a pinch or on a budget....I would buy a swap meet/ebay/fabo 4777 650 Double Pumper....for $100-$250 and put a ProForm 4777 Main body on it with No Choke provisions, and rebuild the carb with Nitrophyl Floats....and 72 Primary Jets and 76 Secondary Jets and 6.5PV and be done with it for about $240.00

The difference is better than just seat of the pants........even with an Auto.