Use the 390 block and stroke it. You can get 431 ci from a 4.125 stroke, or 445 from a 4.25 stroke (That's with a ,030 cleanup bore). Or, if you want 427 ci, you can use your 352 block, bore it .060 and stroke it to 4.125. The good side is you will get a new crankshaft and way better than stock rods. Also get a copy of Barry Rabotnic's "How to build Max-performance Ford FE Engines. There's a wealth of information in there.

If the 390 block can be cleaned up at a 0.010" over bore, you can do the same thing.

Also be aware that there were a few 390 blocks that were cast with very thick cylinder walls. These can be over bored 0.080" to 4.130 which is the 428 cid bore. I have heard they were more commonly found in trucks - I don't know if that is true. If you do find such a block, you want to have the wall thickness measured carefully in all cylinders. One thin spot and you could ruin the block and you still owe the shop for the work done. If something bad happens, it will happen on the last cylinder.

There is an allen wrench test with a freeze plug pulled, that helps identify the thick walled blocks. If a certain size wrench will not fit between cylinders, then the walls are thick. That still does not assure it can be bored that far. Cores can shift and there can be thin spots. The bad news is these blocks are very rare to find now.

I'm going to put this holley side-topic to bed,before it totally side-tracks the new guy's original topic (which was 390 FE's)

The ONLY Holley carbs on this planet that have accelerator pumps on the secondaries, as well as a vacuum diaphragm, are hacked up Frankenstein rebuilds done by mis-mashing the parts together from multiple carbs (I've seen more of these through the years at swap meets, and on craigslist, than I could count) - buyer beware.

Holley NEVER (ever) offered a OEM carburetor part number that had an accelerator pump on the secondaries, AND had vacuum actuated throttle plates on the secondaries.... NEVER. Don't take my world for it- Call Holley product support.

Mr. Davids2toys- Your Craigslist Holley carburetor is either a double pumper, OR it has vacuum secondaries. It's isn't both, unless it is hacked together junk.

The CJ'sPony Parts listing posted above is for a mechanical secondary (aka: double pumper) carb.

The Holley listing posted above is for a vacuum secondary (non double pumper) carb

Your DaVinci carb in your other craigslist ad is correctly identified as a double-pumper

The DP vs vacuum secondary info just posted above was quite helpful. Thanks!

I need to examine the FEs I have. I'm pretty sure the cars they came in were completely played out before the went to the grove. But you definitely make me want to favor the FE.

I have a year to gather parts and study up on FEs, so will do so. I purchased the Rabotnic's book online and will be able to read it on my computer.

I'm not hung up on the displacement number. But it's kind of cool that Dad/Grandpa's old sedan engine might be turned into something fire breathing, in a Cobra replica. It has a certain humor that is appealing.

FE wall thickness test through freeze plug hole
 

This was copied from an article Written by Barry Robotnik - who often visits this site - on the following website http://diyford.com/.

The “Drill Bit Test”

This one test is the single best way to quickly identify an assembled FE block, and credit for it goes to FordFE.com forum member David “Shoe” Schouweiler. You only need the simplest of measuring tools– some drill bits. The following is paraphrased from several of Dave’s responses to block identification questions posed on the forum.

Remove the center freeze plug from the side of the engine block. Using common drill bits, then slip the shank portion of the largest possible bit in between the center cylinder cores through the freeze plug opening. The size of this largest drill bit indicates which water-jacket core was used to cast the block.

If you can only fit a 1/8- or 9/64- inch drill bit shank between the cylinders at the largest gap position on the block, and a 10/64-inch bit doesn’t fit anywhere, then they are 427 water jackets.

406/428/DIF361/DIF391 blocks allow a 13/64-inch drill bit shankto fit into the gap at the largest position.

MCC361FT/MCC391FT blocks (MCC = “mirror 105” marking) allow a 14/64-inch bit to fit between the cores.

Regular 360/390/410 blocks hang around the 17/64- to 19/64-inch water-jacket space at the largest position on the block.

These are only approximations, but tend to be close.

Even if you do have the good jackets, be sure to sonic map the cylinders before boring. If the core has shifted, it could cause problems. It is not at all unusual for FE engines to have considerable core shift. And the oft-raced and abused 427 engines seem to have some of the thinnest cylinders. A block with core shift has cylinders that are thicker on one side and thinner on the other. This can leave the cylinder wall too thin after machining, compromising strength and piston-ring seal.

Confession
 

I was originally thinking I would not mess with a 352 block and only considered the 390. However with a little reading it appears that Ford cast the 352 and 390 blocks pretty much from the same cores. They just bored the 390 bigger. So most 352 blocks can be bored to the 390" 4.050" size and more. That was news to me. You can through the 360 truck engines into this too.

Again there were some thicker walled 390 blocks that can go to the 428 bore.

I literally just read this exact passage from Rabotnick's book. That appears to be a very good reference book; will have to buy a physical copy someday.

Learn something every day. Will keep this nugget of info in mind when I'm selecting a block.

don't forget if you over bore a block and hit air on one of the cylinders just have it sleeved. Not that expensive and you save the block.

I know of a 427 block with four sleeves. Still going strong.

Dwight

Yes, I agree, that ad is mixed up.
I just went out and looked at the Holley 750 vac secondaries I have for sale and you are right, only one pump on the underside. I need to change my ad description...Thanks

You are totally correct. I guess when I looked at it quick it appears to have two pumps because the boss is there for the secondary pump, but there is no pump, it is just as you say. It was in a dimly lit overhead shelf and I looked to quickly. My bad and sorry for the confusion. I did correct my Craigslist ad
Thanks

Just a note as to resolution, I was able to find an engine builder who will build a 390/428 for me. I've frozen my decision-making process to this engine and will build around the engine.

Thanks for all the informative feedback!

make sure your engine builder has build a "lot" of FEs.

If not find another builder.