Max bore size on 340 Resto Block

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2009redrt

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How far would you feel comfortable in bore size on a 4 bolt main, 340 Restoration Block? Trying to decide if I go with custom pistons or bore to the next size. Thanks in advance for any input you may have.
 
Sonic test it carefully. A lot of them are not able to go past 4.07 safely due to core shift.
 
Punched out to 360 without checking. I ended up with the skeleton..
76E6EF6A-2D99-4810-A1B7-C6DA487C90DF.jpeg
 
years ago, a buddy of mine bored out a 360 for 340 pistons. It made pretty good power, too. I thought it was genius, until he cracked a cylinder.
 
Boring for power is not very smart. You'll likely never feel the difference from standard bore to .100 over all else being equal. Stroke is where it's at.
 
2009redrt said:
How far would you feel comfortable in bore size on a 4 bolt main, 340 Restoration Block
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What do you mean by restoration block? A standard 340 block or the "restoration" block that was offered by Mopar Performance (similar to the R3 blocks)?
The latter might go a little bigger, but still I would go only as big as absolutely necessary, as many others have said.
 
Mstall said:
Do you have any pictures of the front of the block? any numbers cast in the front left or right side?
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This is the pic i have. I know it is a R block, first gen.
Never been used. Bought it this summer. Have been in a garage 25 years.

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cool, never saw this before with both lifter angles in the block casting…..any Chance there is another one where this came from? ;-) is it a 4 bolt on the middle mains?

Michael
 
360duster said:
cool, never saw this before with both lifter angles in the block casting…..any Chance there is another one where this came from? ;-) is it a 4 bolt on the middle mains?

Michael
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Well when i saw it i had an X block in the garage.
So i would not buy it before he had lower the price 2 times.
I doubt i will ever find a block like this once more in Sweden .
And yes it is a 4 bolt main caps ;-)
 
I assume that since it's 4 bolt mains, it has filled pan rails, kinda like the 340 6pak blocks? do you have better pics of the bottom end? I assume the big "R" means race block
 
rustycowll69 said:
I assume that since it's 4 bolt mains, it has filled pan rails, kinda like the 340 6pak blocks? do you have better pics of the bottom end? I assume the big "R" means race block
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Here is a pic from when i got it.
Yes it has dilled pan rails ;-) will bore it from its ruff 3,91 to 4,04 and building a real stroker. Aiming a about 700+hp NA

IMG_20180606_170059.jpg
 
360duster said:
cool, never saw this before with both lifter angles in the block casting…..any Chance there is another one where this came from? ;-) is it a 4 bolt on the middle mains?

Michael
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Those first R blocks were before mopar used the term restoration block. On shadydells website it is stated Mopar recommended up to a 4.080, but sonic checking it would be a good investment
 
screw what MP said
just bore it to 4" first build with 360 crank
or 4" stroker
lots more piston choices
block will move around unless you have it heat cycled
you can bore more later
as said stronger walls make more power than a couple of cu in
If you already have a premium 340 crank then 4.040 std 340 first build
stroker is better even if your are road racing
hp is limited by heads and gear spread, you have to back off on the absolute hp to not bog on shifts, even at Bonneville which is really one long drag race
people ask what head
what rpm range do you want?
 
Wyrmrider said:
screw what MP said
just bore it to 4" first build with 360 crank
or 4" stroker
lots more piston choices
block will move around unless you have it heat cycled
you can bore more later
as said stronger walls make more power than a couple of cu in
If you already have a premium 340 crank then 4.040 std 340 first build
stroker is better even if your are road racing
hp is limited by heads and gear spread, you have to back off on the absolute hp to not bog on shifts, even at Bonneville which is really one long drag race
people ask what head
what rpm range do you want?
Click to expand...
Well i have allready bought some nice wiesco 4,04 pistons, eagle h beams rods and a eagle 4" crank. Going for w5 that i bought a couple years ago. Will be a all out dragrace engine.
My w5 vs my indy x head that flow 300cfm.

IMAG0871.jpg


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I have a 59* resto block in the shop now. It's a siamese block at 4.190" bore, and can go to 4.220".
 
B3RE said:
I have a 59* resto block in the shop now. It's a siamese block at 4.190" bore, and can go to 4.220".
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do you know what a 59* r3 will go to on average I know it depends on each block .
 
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