My 1978 F250 has been experiencing some upgrades lately, installed a Weiand stealth intake with a Summit racing series 750 double pump carb which has been challenging to tune. The motor is a 1970 Lincoln Mark III 460 motor, just wondering if I should have bought an Edelbrock instead? Was told by a mechanic that the Edelbrock is much better......see attached

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Should be a fine carb. It all depends on what you can tune. I have read that a 750 is boarder line overkill but it should be fine. With carbs everyone likes what they are familiar with.
Run it and learn about it is what I think.


Nice truck by the way

 

It,s very difficult to tune a carb that has been designed to dump a lot of fuel when the engine can,t use all the fuel its getting. A 750 double pumper is way too much for your engine. A 650 single pumper single feed would be more appropriate.jmo.

 

a holly truck avenger 670 what of been a better choice,

with the intake did you have to extend the throttle cable?

 

Yes, I had to build a bracket and extend the throttle cable and also the transmission kickback lever after installation of the Weiand stealth intake. As far as the carb goes I will have to run it more, its running much smoother now almost too much power when you get on it. The Lincoln 460 has no emissions and stock was 365hp, the carb came with a dvd that had a math formula to figure out how big of carb to buy which pointed me to the 750cfm. Basically the Summit series racing carbs are identical to Holley with float adjustment just cost less. I was told the Edelbrock's are bolt on without the hassle's or adjustments of the Holley/Summit so that's why I am asking. I also installed a 4 core aluminum radiator with a single wire HEI distributor, definitely woke the motor up quite a bit overall.

 

Agree the double pumper is best for light race cars... not so good for a heavy truck.

You want vacuum operated secondaries... either Holly or Edelbrock can be fine. I think Summit offers a Holly vacuum secondary clone that may be suitable.

If you do go with Edelbrock, fuel pressure needs to be kept below 5 psi which often requires a regulator.

 

Ive been running a holley 750...not a double pumper....on my 79 F350 w/460....ive really had great results with it as far as the truck running...whoooo really drinks gas

 

I put the summit street strip 600 on my truck and it does just fine same carb has been ran on my 390 dads 400 and a buddy's mild built 460 all ran peachy

 

You really need to read up on tuning a Holley double pumper. Lots of good walkthroughs with pictures or videos on youtube. There is the jets, the power valve, the accelerator pump cams, etc. There is a certain order and you can get them dialed in quite nicely.

Don't ever expect a carb to be set up correctly out of the box.

Yes the 750 is a little on the big side. You lose velocity through the carb at lower RPMs with too big a carb that can make it not run correctly.

 

The consensus I am receiving for feedback is the 750cfm double pumper is not ideal, but could possibly be adjusted to tune better. I did get a video with the carb explaining that the jets would be the first change if necessary. I bought this carb right through Summit, but now am considering a different carb in the future. My truck only has 9,000 original mi on it sat for a long time and I am slowly working out the bugs so to speak. I have noticed a big surge in power to the point where I don't trust my 16 yr old son to drive it even though he badly wants to.

 

I said in an earlier post that I did have to extend the throttle cable, but that is not true only the transmission kickback lever.

 

Thank you, advice is always taken.