My truck is out of commission for a little while. Waiting on parts. So I started thinking about replacing the carb & intake. The last owner randomly removed a lot of the emissions stuff and I switched the carb over to manual choke so I would have more control trying to get it dialled in. I think I've likely got a leak in the intake letting air in. I figured if I'm going to pull it off why not replace it. So here's what I'm looking at.


-Edelbrock 1405 carburetor
-Edelbrock 2171 intake manifold
- ??.... Is there anything else I would need to complete this and/or anything I should do while doing this?

I've read that I should be upgrading the exhaust also. Can anyone tell me of any (bolt on..with little or no modifications) upgrades I can do to the exaust....manifolds?..headers?.... Magic things?
Thanks


((Disclaimer - I have never done any of this before. Learning as I go.))

 

Opinions are like A*#Holes, everyone has one, That being said, what intake is on the motor now? some are as good as the ebrock replacements or better, I like Vacuum secondary Quadrajet Carbs and would be my suggestion, but, if your are new to carbs you might want to look at that new street demon - https://www.holley.com/brands/demon/

or just run what you got on top and put the $$$ towards exhaust..

GL

 

Here we go with another opinion.....so here it goes. haha. I ran a Carter 625 on the Edelbrock 2171 manifold and LOVED it. Never had a problem with that combo and ran it for 20years before I got that carb rebuilt. Use a 1 inch carb spacer for good results. As for exhaust....I bought a pair of Dynomax headers to replace the Cyclone headers I bought in 1987. Had to completely remove the factory exhaust and have a muffler shop redo the exhaust from the collectors back. I ran 2 1/4in exhaust. Sounded real good with 31in glass packs.

 

I am new to carbs. Pretty much new to all of this. My only criteria so far is
-manual choke
-stuff that bolt on without cutting, welding or generally being a pain in the ***.

Right now everything is stock. Except the emissions stuff and original automatic choke were butchered.

 

Would you mind explaining what "vacuum secondaries" are?

 

First off there was only one factory manifold for the 351m/400 that I've ever heard of. It's not a performane piece by any means. The only real option would be an edlebrock performer., unless your going to go full out performance, I'd use a 600 Holley, vacuum secondary.

The stock setup uses a block under the carb for EGR. They are famous for eating themselves up inside where you can't see it. Intermitent vaccuum leak is the result.

 

Let Google search B UR Friend - I input "Vacuum Secondaries" and 10 billion links magically appeared - Here's just one - JEGS

 

Yep. Dumb question. Sounded more complicated then it is.

" Should I use a vacuum secondary or mechanical secondary carburetor?
Answer: For street cars the vacuum secondary carburetor works best on most cars with an automatic transmission. They are more forgiving than a mechanical secondary because they work by sensing engine load. The mechanical secondary carb is best on a lighter car with a radical camshaft, a lower gear, and manual transmission. A mechanical secondary is the best choice for most high RPM race purposes."

 

My original questions. I've also emailed Summit. Based on what I've read this combination will work fine. I emailed Summit and would also ask again here if I should order anything beside these two items to complete the swap? I read along the way somewhere that the factory fuel pump puts out too much pressure....I'm not sure if that applies here? I'm guessing that it doesn't. I'm hoping to hear back from the Summit tech soon.

-Edelbrock 1405 carburetor
-Edelbrock 2171 intake manifold
- ??.... Is there anything else I would need to complete this and/or anything I should do while doing this?

 

Make sure gaskets come with the new parts. Good luck with it.

 

Don't use an intake manifold gasket, get a valley pan gasket instead.

 

I was reading about the valley pans. I figure I should pull that out with the old manifold, clean it and re-install with new gaskets as well?

 

I have had that same Edelbrock Performer 400 intake since the late '80s ..... had a Holley 600 vac sec list 1850 on it until a few years ago ..... now have the Edelbrock 1405 on it.

Ford 351M and 400 oem mechanical fuel pumps are rated to 7 psi. Holley carbs can tolerate 7 psi. Motorcraft oem carbs can tolerate 7 psi. Edelbrock carbs have different shaped floats, different leverage between float pivot - inlet needle - float .... and Edelbrock carbs do not like more than about 6 psi max, 5.5 works well. You can throw money away on a cheap MrG or Spectra fuel pressure regulator or go ahead and get a Holley #12-803 adjustable fuel pressure regulator and beg / borrow / buy a pressure test gage to use to set it at 5.5 psi ...... or forever have flooding at idle and low speed.

Once dialed in, I'm tickled pink with the setup. I might have a bit too much cam, it is an old late '80s Crane Fireball cam ..... .484 / .510 lift is all I recall for sure, 282 / 292 degrees duration maybe, it was a "torque" grind as I recall. Cam timing is set straight up using three way keyed timing set.

I did this all shortly after buying the truck in 1986, I still have it ...... still plugging along. It is a 351m but I have a 400 on a stand almost ready to go in ..... but the 351m just runs so good ......

I also have a advance spring kit that speeds distributor centrifugal advance up, I set total timing with centrifugal all in at 35 BTC with vac unhooked, then hook vac back up.

Just my experience.

 

Thanks for the information. Summit has the Holley pressure regulators for $29.67. I put one in my shopping cart. I'm going to pull the trigger as soon as $$$ allows.

 

The Summit house brand carb is another option.