I changed out the oil pump and dizzy so I can put on a newer carb. The car is a 54 capri. Trying to figure out the cfm for it. I've been looking at 500 cfm 4 bbl. Is this the best choice? Engine is stock, no high performance parts. Would 600 work okay? What size was the original carb? My engine didn't come with one.

Brad
Sierra Vista Arizona
1954 Lincoln Capri

That LYB engine will run just fine with up to a 600cfm vacuum secondary carburetor on it.  Keep in mind that the secondaries will only open the amount that the engine demands assuming one does not tinker with the secondary spring rate or convert the secondaries to mechanical operation.  The Summit 500cfm carburetor is good fit for most stock cammed engines and for those that are hesitant to use the slightly larger 600 or 750 versions.
Summit Racing SUM-M08500VS Summit Racing™ M2008 Series Carburetors | Summit Racing

Lorena, Texas (South of Waco)

I would agree with Ted that the 500 cfm Summit would be a better/good fit for the Lincoln Y.  I have flowed and ported one of those 4V intakes manifolds for another forum member, and it was a terrible intake manifold.  As I told him, it is probably the lowest flowing Ford/LM intake that I have ever tried to flow and port.  Some of the runners were only flowing in the 110-120cfm range.  Don't over carburate it!  JMO, Joe-JDC

JDC

So if I was to find a decent 350 to 400 cfm, that would probably be more appropriate for my engine?

Brad
Sierra Vista Arizona
1954 Lincoln Capri

How about a 390 CFM Holley 8007-0. I have had a couple on my 56 292 and my friends 56 with 292. They come new with 51 main Jets but other than replacing them with 56-60 Jets no other Mods needed. I replaced Needle and Seats with all Steel Units meant for Alcohol Engines so no problem with sticking Inlet Needle. Never had any problem with them.

  

The Summit carb is a better carb for these vintage vehicles which sit several days to several weeks at a time because it is a bowl style carb instead of the sandwich metering blocks of the 4150/4160 Holley style carbs.  If you can install the air filter assembly on the Summit, I would recommend it.  I have the 750VS on my Thunderbird, and I can let it sit for a month and it will still start in the south TX heat.  Joe-JDC

JDC

Anyone have knowledge of a Edelbrock 1403? I found one at a decent price. New. 500 cfm 4 bbl

Brad
Sierra Vista Arizona
1954 Lincoln Capri