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Hi guys..
Well a few months backk I passed on a 352 for $250 and it was right around the corner from me... but
I do that a lot.
But I have a question to some of you who might build engines, which I have really not done...

taking a 352 and boring it to 4.23 (same bore as the 427) but leave the 3.50 stroke you get a 393 + -
I used an online calculated for that equation BTW

Now would you need to use a 427 pistons

and over square high rev FE.. probably roller lifters and rockers...
open up the intake valve...
What are your thoughts?
 

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I brought a D4TW 390 in to machine shop to see if it could be bored for a 428, the answer was no, not enough room on the thrust side.
 

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Hi guys..
Well a few months backk I passed on a 352 for $250 and it was right around the corner from me... but
I do that a lot.
But I have a question to some of you who might build engines, which I have really not done...

taking a 352 and boring it to 4.23 (same bore as the 427) but leave the 3.50 stroke you get a 393 + -
I used an online calculated for that equation BTW

Now would you need to use a 427 pistons

and over square high rev FE.. probably roller lifters and rockers...
open up the intake valve...
What are your thoughts?
FE blocks in general have fairly thin cylinder walls.

For example; a 390 4.05" bored to 428 bore 4.13" will result in *very* thin walls if not actually punch thru.
That's "only" an 0.080" overbore.
At the very least, it will probably be porous, and stick a light in the bore and you have a Chinese Lantern. :)
Oh sure, there will be a bunch of guys that claim they did that and it's just fine.
I say, show me proof.

As was already stated, good luck taking a 352 out to 4.23".
You may as well be boring it out for sleeves.
 

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You are getting good advice

I hate absolutes, but....there is no 352 that can go to 4.23 and not split a cylinder. 427 blocks are completely different

Very few 352 blocks can go 4.13 (428 bore) because 428 blocks are different (but not as different as a 427) and those that do, still risk splitting a block or becoming porous at some pit inside the water jacket from the backside. Guys will say they do 4.13 bore 390s all the time, well if they do, they don't build much power, or they go through a pile of blocks doing sonic checks.

More than anything though, remember, a strong stable cylinder makes more power and lasts longer than a larger one that is more flexible. Rings are designed to seal inside a cylinder with stable dimensions, the thinner the cylinder wall, the worse the ring seal gets and power goes down, and rings have to flex to follow, taking life out of them.

I would much rather see you build a 390 out of the 352, balance it, use light components and spin it to 7000, or leave 352 bore and add a 3.98 or even 4.25 crank and make even more power at lower RPM.
 
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