Holley 670 vs 750

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   would it be easier to just get a 750 DP with mechanical secondaries?

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drumcrazd Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Oct/17/2015 Location: Ontario Canada Status: Offline Points: 35	Post Options Post Reply Quote drumcrazd Report Post Thanks(0) Quote Reply Posted: Jun/20/2021 at 8:48am
	would it be easier to just get a 750 DP with mechanical secondaries?

Heavy 488 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Apr/27/2019 Location: In the Status: Offline Points: 3553	Post Options Post Reply Quote Heavy 488 Report Post Thanks(0) Quote Reply Posted: Jun/20/2021 at 9:04am
	Dual pumper is mechanical secondaries

ccowx Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Nov/03/2010 Location: Yukon Status: Offline Points: 3510	Post Options Post Reply Quote ccowx Report Post Thanks(0) Quote Reply Posted: Jun/20/2021 at 11:33am
	Either carb (670/750) would work fine, just depends on your driving style and tastes. The DP is nice if you have a light car with stiff rear gears and a four speed etc. If the car accelerates too quickly and the airflow can't start picking up fuel from the main jets before it runs out of accelerator pump shot, then you need a DP. Probably if you are getting 0-60 in under 5 seconds or so is around the point where this starts to happen. Of course every engine/combo is a bit different, depending on camshaft, intake, tire size etc. but that might give you some sense. I am going to guess that with the 3.15 gears you are good with a vac secondary Holley. A DP might give a bit more smoothness, but at the expense of mileage. I would think that single accelerator pump like a 750 cfm list#3310 Holley with an aggressively tuned accelerator pump will work fine. 31 squirter and a green or orange pump cam should get you close. A bit of time spent here will yield benefits in happiness on the road. We can walk you through it, it's not hard or expensive. Chris