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  #1  
Old 05-06-2004, 06:34 PM
CorpseEater CorpseEater is offline
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Default Need to find how far a 360 has been bored out

I have a 1973 duster which has a 318 small block in it. I am in the process of getting a 360 small block which is coming out of i believe a 1962 dodge pickup. I was told that the engine has been bored out to 440hp but i don't know much about cars. Is there a way to be able to tell if this is true without paying a mechanic to find out?
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Old 05-06-2004, 07:16 PM
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ehostler ehostler is offline
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I can assure you that it hasn't been bored out to 440hp. HP is dependant on a LOT more than just an over bore.

You will need to pull a head off and then mic the cylinder bore. Take that measurment and subtract 4" (4.00" is the standard bore of a 360) from it. That will tell you the amount of over bore.

To determine the current CID, use this formula - bore X bore X stroke X .78539 X 8 (number of cylinders).

Example - bore = 4.00" stroke = 3.58"

4 X 4 = 16
16 X 3.58 = 57.28
57.28 X .78539 = 44.987
44.987 X 8 = 359.896 CID
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Old 05-07-2004, 02:07 PM
451Mopar 451Mopar is offline
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Well first the 360 small block was first avaliable in 1971, so if it's from an earlier truck, it sure wasn't stock.
Maybe they meant the engine was a 361 Big block?
Either way, neither can be bored to 440 cid.

On the side of the engine block there should be the size cast, also on the front of the block, right below the drivers side cylinder head the engine size should be stamped into the block.
A 360 has a stock bore size of 4.00" and stroke of 3.58"
About the most overbore you would want is 0.040" over, or a bore size of 4.040".
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Old 05-07-2004, 02:30 PM
Plymouth10 Plymouth10 is offline
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quick way to check is look at the balancer 360s were external balance and have a larger elongated type balancer,compared to an internal balance, bored out to 440? ci no 71-72 blocks can go well over 0.90 over,but........ check the cid stamp on side of block as mentioned. to see what you got. could be a poly 318 as well
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Old 05-09-2004, 01:32 AM
CorpseEater CorpseEater is offline
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I just wanted to thank you guys for the replies that you have left me. It will definitly help me out on the engine i'm looking at to tell how far it has been bored out. Like i said before i really don't know much mechanically about cars so i might be back here asking more questions really soon for the simple fact that i need to get my 73 duster fixed up good. Once again thank you for the information.

Corpse Eater
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  #6  
Old 05-09-2004, 01:56 AM
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MoparMarcIdaho MoparMarcIdaho is offline
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Question didnt the early 360s have steel cranks?

seems to me I have one somewhere,Ill look.
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Old 05-09-2004, 02:07 AM
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dwc43 dwc43 is offline
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360's have cast cranks. About .060 is about as far as you want to bore them over too.
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Old 05-09-2004, 05:31 PM
Plymouth10 Plymouth10 is offline
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71-72 360 blocks are 340 cores, with the same cylinder spacing and can be overboard quite a bit .040just would take it to were a normal 340 would be, still lots of room, depends, weve gone .090 over on at least 3. {.050 over 340 standard bore} 71 72 blocks are getting very hard to find and have a high nickel content as well.
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Old 05-09-2004, 07:41 PM
jelsr jelsr is offline
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If there is a question about 360 or 361, the distributer is in the back on the 360 and the RH front if a 361. As was mentioned the 360 is a '71 and later. The '62 is about right for a 361.
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Old 05-09-2004, 10:34 PM
CorpseEater CorpseEater is offline
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I have one more question. How can you tell what the stroke is on the engine?
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Old 05-09-2004, 11:33 PM
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MoparMarcIdaho MoparMarcIdaho is offline
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Arrow just measure it

from the bottom as far down as the piston will go to the top.
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