340 w/ 650 double pumper ?

If you have the $ Holley hp carbs are the best. Has no choke but the mettering blocks idle circuits are better so you really do not miss the choke. It comes in DP and vacuum types. I have a 750 DP on my 318 with 3.91 gears and a low gear set up on my 904 trans so first is close to 4.56 gears. Now even then when I had the MSD 6 box I needed to slowly-like 1 good full second-put my foot on the gas all the way down or sometimes it bog a little. I switch to a MSD 7 and now I can just punch it from a dead stop and it justs takes right off if the wheel don't spin. Helps to have a full tank of gas and stay of the blacktop. Some roads are much better than others.

I sometimes-mostly before I got my MSD 7-wish I got a vacuum 750 HP but only at slow speeds in the wrong gear its too big. If you can just buy the carb. I go with a vacuum one or maybe a 650 but you need to be able to burn all that gas the carb will force in it. Wish I would have know sooner how much better a racing spark box would help. Guess thats why they say DP only for racing. You need all the racing stuff, headers, intake and a good strong spark.