340 vs. 360 build?

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URDUST73

time for the COLD wrench!
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Hey guys I am new to the site and have been researching this since before I even joined. I have a 73' Duster w/ the 318/727 combo. I am wanting to build it up for street/strip performance nothing super crazy like no big block swaps or anything. I am expecting to have to rebuild whatever motor I get though and will be upgrading to some more performance oriented parts.

I can get a 360 from this guy for $200 right now but I am still looking for a good deal on a 340 six pak (hard to find). I would rather put more money into upgrading parts than just buying a motor. Also would I have any problems w/ either of those motors bolting up to the 727 tranny?
I am looking to get the car into the 12's or better. I plan on a 410 gear, locker, ratchet shifter, upgrading fuel system, spark system, intake, carbs, possibly new heads or at least rebuilt, and internals, possibly stroker kit. Is it possible to drop a six pak onto a 360 or what would the best carb/intake option be for the 360?
Thanks everyone for your opinions and hopefully I can get pointed in the right direction.
 
Usually 340's rev better and are better for racing but 360's give more torque, like for the street (not an expert,just repeating what I have been told).
 
I can get a 360 from this guy for $200 right now but I am still looking for a good deal on a 340 six pak (hard to find). I would rather put more money into upgrading parts than just buying a motor. Also would I have any problems w/ either of those motors bolting up to the 727 tranny?
I am looking to get the car into the 12's or better. I plan on a 410 gear, locker, ratchet shifter, upgrading fuel system, spark system, intake, carbs, possibly new heads or at least rebuilt, and internals, possibly stroker kit. Is it possible to drop a six pak onto a 360 or what would the best carb/intake option be for the 360?
Thanks everyone for your opinions and hopefully I can get pointed in the right direction
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Do the 360 for hundreds cheaper and get more torque and peak power a few hundred RPM's sooner.
A 6 pac will bolt onto any small block except the early 273 heads. It'll bolt up to any small block tranny. No problem.
The best IMO intake and carb combo is a RPM and a carb of your choice. I like the Carters. Holleys and opthers are just fine as well. It's a YOUR choice thing.

12's are easy and well writin here.
 
thanks. I was leaning toward the 360 but at the same time the 340 is nice because the rarity, but i guess that defeats the purpose of hot rodding it.
 
I like the link and build to a point.
 
I had thought about that as well. However I have someone lined up to buy my 318 for the price I can get the 360 for. So really I am not out any $$ by getting the 360 motor. Just starting w/ a better platform. Thanks for the link though.
 
i say for the money go with the 360.. nothing wrong with a 340 but a 360 is way easier and cheaper to get... to get a 360 into the 12,s is cake too...
 
If the 360 is available go that route,i myself prefer 340's...good move though yanking the boat anchor out......
 
360 bored 030, decked for zero deck height, Diamond forged flat top pistons, SIR rods, Edelbrock LA style heads 63cc to give .040 quench with .040" Cometic hd gasket, 1.6/1.5 RR assembly and moly pushrods, Racer Brown or Bullet hydraulic cam in the 240-244*@.050 w/ ±.520 lift and springs to match, Eddy Airgap intake, 650 Mighty Demon carb., 3500 stall TC (no cheapy), 3.91 gears and a good set of headers like TTis will give you a great street/strip combo and run mid - low 12s in an A-body with a reasonable suspension setup.
Now go have some fun.

Save the 340 for the resto guys.
 
I'll go 388's build similarly. But you dont even need Edelbrock heads, rods, or a real high stall. Just good solid performance work and parts. It will run mid 12s with 375hp in a drag race set street car. You can build an engine like that for under $4K.
 
What Rumblefish, 388 and Moper said.......two thumbs up. 12's are so easy with that combo I would believe something was wrong if it was so slow as to NOT get into the mid 12's @ 108-110 mph. Good luck, Terry.
 
Id say 360, My car has the original 340 and thats why I would look for another 340 to put in it IF i ever needed another engine..BUT if I had a non original car id just build the 360...20 FREE extra Cubes plus cheaper parts and you can build it to rev just as much as the 340 IF you buy the right parts.....Heck I think IF i ever needed another engine and I priced it out I MAY even go with the 360 just for the price savings....
 
If you want instant power with little mods then go 340...a good high compression one that is.....there already built from the factory but with the 360 route nearly everything will have to be replaced or upgraded. they were never really intended to be a high performance motor..though if you get your hands on a 360 police motor you have a great starting point
 
71duster06 said:
If you want instant power with little mods then go 340...a good high compression one that is.....there already built from the factory but with the 360 route nearly everything will have to be replaced or upgraded. they were never really intended to be a high performance motor..though if you get your hands on a 360 police motor you have a great starting point
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Most likely he will be rebuilding the motor anyway so at that point why not get the extra 20 cubic inches that the 360 has to offer. A lot of 360s came through as low compression smog motors but once you bring that compression up (piston swap) to the level of a 340 you have the same power and torque but coming in at a lower RPM which is great for a street car.
 
71duster06 said:
If you want instant power with little mods then go 340...a good high compression one that is.....there already built from the factory but with the 360 route nearly everything will have to be replaced or upgraded. they were never really intended to be a high performance motor..though if you get your hands on a 360 police motor you have a great starting point
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The problem with this train of thought is that any 340 is allready35 years old and beat on. So, then comes the rebuild which will need everything a 360 gets except when it comes to a converter for balanceing. B&M flex plate solves this issue for a neutral balanced converter.

Has anybody done a 340 vs 360 piston cost look lately? Hummmmmmm

The only thing a 360 is going to have upgraded is pistons. But like I said, since there being replaced anyway in ethier engine build up...........
 
71duster06 said:
numbers matching 340 with a 8 1/4" rear end?????
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Yes! The 8.75 was replaced by the 8.25 in 73 as the heavy duty axle for A-bodies. This was also the first year for A-bodies getting large bolt pattern wheels.

Regarding which engine to build! The original poster does not have either but has a chance to pick up a 360 for $200. You are very unlikely to find a rebuildable 340 core for under $600, the restoration crowd has driven the proce up not because they are better. That plus the slight cost advantage for 360 pistons you can easily build a 360 for several hundred dollars less and make more power that an equivalent 340.
 
new idea big block a body nothing like it!!!!!!
 
you can get some mean power out of a built 318. do that...you already have the set up...do a stroker kit on that...
 
My 2 cents, build the 360 usless you have to meet some class rule.
3.58" stroke 360, 3.31" for the 340, the 360 will need to have it's
compression raised, most 360's were only 8:1 compression at best.
 
rumblefish360 said:
The problem with this train of thought is that any 340 is allready35 years old and beat on. So, then comes the rebuild which will need everything a 360 gets except when it comes to a converter for balanceing. B&M flex plate solves this issue for a neutral balanced converter.

Has anybody done a 340 vs 360 piston cost look lately? Hummmmmmm

The only thing a 360 is going to have upgraded is pistons. But like I said, since there being replaced anyway in ethier engine build up...........
Click to expand...

I agree with a 360 being easier to get and cheaper,but the keith black pistons for a 340 are pretty reasonable at only $250.00,not bad considering.I would build a 360 hands down if I was starting from scratch,but I had to have 340 since mine is original 340 four speed,even though my 340 is not numbers matching it just wouldnt feel the same to have a 360 lol.
 
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