360 build or 340???

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We have 2 stroked 340's and a stroked 360. The 340's are my dads, one is a 416 and the other is a 422. The 360 is mine and its a 408.
 
Nothing wrong with the 360! Back in early 1975, I purchased a traded in 74 W-200 Power Wagon. It had been flooded up to the headlights. Got it right. At the time, I was working with a friend of mine in a auto machine shop. I decided to warm the 360 up a bit. Total disassemle, and cleaning. No ring ridge to speak of so just a nice honing to the cylinders. Balanced the rotating assembly. Installed a 340 windage tray, enlarged the oil pan with a with a 2" wide band and installed a Melling HV oil pump. Installed a Crane Blazer hyd. cam with a Cloyes double roller chain, at 4 degrees advance. Back then the Blazer was a hotter cam the the later ones. Ported and polished the heads and a 5 angle valve job. Topped it off with a Edelbrock 2-4bl manifold with a matched set of old Carter AFBs off a hemi. Had a rod shop set up my stock HEI distributor with mechanical advance. Put a B&M shift kit in the 727 trans. What a bear it turned out to be. And it still is. The only thing I have changed through the years is that I went to a single Edelbrock AFB on a stock cast iron manifold. I was towing a 35 ft 5th wheel camper. It's still my playtoy and is pictured with my 47 dodge pickup. Good luck with either direction you go with, but don't be afraid of the 360 build. countrygent
 
1968FormulaS340 said:
Like most have said... If you have the 360, just build the 360... Really you can build the 360 to do about anything a 340 would do. You just won't be able to tell people you have a 340...


340 to 360 in reality comes down to .... Do you want the 340 bragging rights.
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Plenty of 340 envy around. :-D
 
On the kit shown, I would shy away from any hypereutectic piston for a 4" engine, and I personally dont use SIR rods, although others here have had good results.
 
Hi guys!!! I'm a new member but an old diehard mopar fan. I have a 360 Premium out of a 78 Diplomat...What's the difference between a regular 360 and a "premium" I am looking to build it up to replace my gently built 318...Any help would be appreciated... Thanks
 
Like the guy's have said 340 is great if you can find one you can afford. But if something should happen to it trying to find another could be a big problem. If you build the 360 and throw a rod, another block won't break the bank.
 
Hey Shadowdog!!! You seem to know abour 360's. I have a 360 with the words "premium" on the valve covers. It came out of a 78 Diplomat from the original owner and I was told that it may be a "Police" 360..... Any thoughts ??? And the stroker kit you pictured in your forum post for the 360 to a 408 kit... What horsepower should a guy expect out of it with a decent set of stock heads??? I want to build this one up over this coming winter and needs to budget ahead of time...like the most of us....Thanks ahead for any advice.....Rockin' Ronnie
 
If I didn't get a 340 SB for free a few years ago, I would be putting a 360 combo in the Valiant. It's cheaper to buy, easier to find, and was designed as a torque motor from the get-go. I'm not part of the "Numbers matching" fanatics, but the block is from '69 as is my Valiant. Should piss off a few folks, but it's my stuff and I have no clue what happened to the car it came from!
 
I have a 72 340 steel crank 340. Does that mean I'm Damed? Yes, I agree that a motor with 20 cubic inches more gives you an advantage. But at the same time, there are certain advantages built into certain engine desigatiations that are above the average because of the ideal conjunction of the right parts. Just like the old 283 Chebby held track records of years, their are many other combo's that have an advantage over over stroke/bore/head combo's.The old 331 SBC combo was super great for GM but for Mopar the deal was the 340. Remember Bob Glidden?
 
no brainer. go with the 360, the 340 is better thing is just an old school thing carried over from when there were no performance pistons out there for the 360.
 
6T9 V-100 said:
If I didn't get a 340 SB for free a few years ago, I would be putting a 360 combo in the Valiant. It's cheaper to buy, easier to find, and was designed as a torque motor from the get-go. I'm not part of the "Numbers matching" fanatics, but the block is from '69 as is my Valiant. Should piss off a few folks, but it's my stuff and I have no clue what happened to the car it came from!
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Huh? What does this post mean? Why would anyone get pissed off about a A-body motor?
 
strang3majik said:
Well, I say 360 for two reasons,
one, you have it already.
Second, there is no replacement for displacement. Part of what made me make my decision, was looking through Mopar Muscle, and realizing that, they don't build crate 340s. They only build 360s. There is a reason for that...[/thread] :)

Same with a 383 vs 400. Everyone shouts 383, 383! However, the 400 is just as strong, if not stronger. The problem is, everyone knows the 360 and 400 in the smog years, therefore think they're nothing, but, that just isn't so.

Tell me this. Would you stroke a 340 if you had one to build, and an unlimited budget?

If you answered yes to the above question, do you realize that is the only difference between a 340 and 360?
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Mopar Performance/Direct Connection has an entire line of crate motors based on their 340 replacement block. They also have a siamese 340 block that is available stroked up to 440". The 360 crate motors don't come anywhere near these in performance or potential.
 
abodyjoe said:
no brainer. go with the 360, the 340 is better thing is just an old school thing carried over from when there were no performance pistons out there for the 360.
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I think there's a little more to it than that...The 360 is a truck motor. The 340 was never anything but a quasi-race motor...never had a two barrel, always had a double roller chain, ect. The T/A was based on the 340. The X blocks were based on the 340, and that was back when the 360 was taking over. The R blocks, were based on the 340, and they turned into the whole R-family. The 360 evolved and took over the position of production, performance, small block, but the 340 evolved and turned into THE full out race motor. The 340 enjoys that celebrity regardless of how a 360 performs.
If this decision were mine, I would build the 360. Fortunately I have 340s. (I just took the T/A 340 out of my Demon and sold it to the E-body crowd.) The 360 has taken over the aftermarket, and that is enough of an excuse for me to go 360. Cheap parts. However if I were building a stick car...I'd put a forged crank in it.
 
Rockin Ronnie said:
Hey Shadowdog!!! You seem to know abour 360's. I have a 360 with the words "premium" on the valve covers. It came out of a 78 Diplomat from the original owner and I was told that it may be a "Police" 360..... Any thoughts ??? And the stroker kit you pictured in your forum post for the 360 to a 408 kit... What horsepower should a guy expect out of it with a decent set of stock heads??? I want to build this one up over this coming winter and needs to budget ahead of time...like the most of us....Thanks ahead for any advice.....Rockin' Ronnie
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RR
Best way to tell if it was from a cop car is to look at the # stamped on the block since the valve covers could have come from another source usually there wil be a "P" or "HPP" if you have "HPP" it has a bit more compression and cam in it "P" just mild cam.
As far as HP with that kit..depending on cam and compression you could build up to 500HP. I would get a better crank if you want more than that out of it. I would take the time to gasket match your flanges...it's worth the trouble. Bronze alloy guides, hardened exhaust seats. Springs to match your cam. I allways have .030 milled off the heads...but check valve clearance if going over 9.5 pistons.Most common mistake I see is over carbing the 360 or running too rich. You need to adjust for your elevation. Here in Roswell I drop down 2 orfice sizes on holly 4160 since we are at 3600ft. Use either manual secondarys or the weakest spring for vacum secondarys. If your going to keep it street the air gap Edelbrock preformer is good...if you have the clearance a 2" 4 hole spacer on top will make it work better. Unless your running 12:1 or higher comp and a radical cam I would stay at 600-650 cfm.
Anything that robs HP is good to look at---it all adds up. Go to undersized pullys and HP water pump. Equal length headers. Windage tray helps too but I don't see any gain with a valley baffle. Use an electric fuel pump and toss the manual one out.
Hope this helps...

SD
 
Outsider said:
I think there's a little more to it than that...The 360 is a truck motor. The 340 was never anything but a quasi-race motor...never had a two barrel, always had a double roller chain, ect. The T/A was based on the 340. The X blocks were based on the 340, and that was back when the 360 was taking over. The R blocks, were based on the 340, and they turned into the whole R-family. The 360 evolved and took over the position of production, performance, small block, but the 340 evolved and turned into THE full out race motor. The 340 enjoys that celebrity regardless of how a 360 performs.
If this decision were mine, I would build the 360. Fortunately I have 340s. (I just took the T/A 340 out of my Demon and sold it to the E-body crowd.) The 360 has taken over the aftermarket, and that is enough of an excuse for me to go 360. Cheap parts. However if I were building a stick car...I'd put a forged crank in it.
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who cares what they were from the factory. and i'm not talking race blocks or even TA blocks here. i'm talking standard production blocks. the 360 wasn't liked by the old school because as you say was a truck motor,low compression and no performance pistons for them just like the 400 that everyone wants now. that was then. this is now. and there are plenty of pistons out there for a 360. a 360 is more readily avalible and at more reasonable prces then a 340. leave the 340 for the numbers guys and build a 360 to run.
 
abodyjoe said:
who cares what they were from the factory. and i'm not talking race blocks or even TA blocks here. i'm talking standard production blocks. the 360 wasn't liked by the old school because as you say was a truck motor,low compression and no performance pistons for them just like the 400 that everyone wants now. that was then. this is now. and there are plenty of pistons out there for a 360. a 360 is more readily avalible and at more reasonable prces then a 340. leave the 340 for the numbers guys and build a 360 to run.
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Thats what Im saying. They are unliked because they were smog motors. The 360 and 400. But, people don't realize why they were bigger. Too make up for the fact they were bogged down, they had to make more torque out of them...answer to that...stroke them out.
I don't know about you guys. But, the 360 is my choice...hands down.
 
Hey Outsider- sorry if I sounded obtuse. One of my closest friends is into Corvettes, but he is no pr*ck about it. He just enjoys the car and laughs aout those jackholes who are into "The Corvette Lifestyle." One time he invited me to go to a club meeting and off the bat he said "Oh, you'll get a good laugh outta this." There were some really good folks there, but there were the others there,too. It was almost like the car was a 'compensator' for the person's lack of _______. Sadly, I've seen some of this personality trait showing up at Mopar shows over the last few years,too. I'm sure when the car is done and if I take it to a show, somebody will make a comment about the Valiant having a 340 in it instead of a "Proper" 340 car having a correct era block. That was the reason behind the comment!
 
I say build the 360 you already have. For the cost of locating a 340 and buying it and getting it home(not even starting to build it) you can buy a cast 4" crank ($300), H-beams($300) and forged pistons($500) for your 360 all delivered to your door.OR, some EQ Magnum heads, OR etccccc.....Get the picture?I do love 340's but a cost/benefit analysis doesn't favor it! ( Unless you get super lucky and your neighbor has a free 340 waiting for you!)
 
Outsider said:
Mopar Performance/Direct Connection has an entire line of crate motors based on their 340 replacement block. They also have a siamese 340 block that is available stroked up to 440". The 360 crate motors don't come anywhere near these in performance or potential.
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Outsider, the folks at MP are no dummies. The Product Marketing people (read advertising guys) certainly understood the benefit of selling "340" blocks instead "360" blocks to Mopar guys.It's more of a Marketing thing. Fact is, everyone bores and strokes everything anyway. Why not ride the free adverstising coatails of the Legendary 340? What small block Chrysler evokes more passion than a 340? They could have called it the SLAB " Super L A Block" but it just wouldn't have the same ring to it! You'll sell more $$ worth of parts! Why do you think they brought back the HEMI and pasted it all over both cars and trucks? Marketing, pure and simple. All things being equal (compression, cam, valves, heads,etc.) the 360's 20 more inches would have the advantage(albeit slim)over the 340. It's moving more combustable fuel/air and thus should create more energy.
 
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