340 4 speed vs 5.2 5 speed

-
ValerianMagnum

ValerianMagnum

the little car that could
Joined
Mar 17, 2008
Messages
1,153
Reaction score
465
Location
montreal , canada
5.2 magnum roller cam ( stock ) , better flowing heads, good flowing manifolds , fuel injection regular gas , 3x31 stroke same as 340, lighter rotating assembly., 230 net hp / 300 torque, streetable 9.0:1 compression VS the "Mighty" 340... 300 hp approx and 340 torque ( gross ) specs and mechanical cam and 10.1 + compression etc high premium gas , parts harder to find and need hardened seat for todays gas Carburated car in a hard 4 season city ....who is better than who and why , i think in 2020 the 5.2 as a better rep but not enough respect and i love the 340 but i think its a bit overated compared to everything that we can have now as v8 power plants.....dont bring a 360 5.9 magnum, i know, i know that is a better powerplant and even the 5.7 gen3 hemi is even better too bla bla bla *** talking about a real battle between stock vs stock , sure a 5.2 5 speed can take a 340 4 speed in the same body..What do you guys think , be honest and yes i have both mecanics laying around and i dont have a matching number # 340+ 4 speed mechanic but the car is a h code car , i dont want to rebuild the 340 id rather keep it the corner and have fun with a cheap build, thats my opinion
 
Son, I've been in a 4300 pound '73 Charger with a 340 rebuilt 340 that was set up with 10.5:1, X heads, MP stock replacement purple shaft. Had a stock '73 iron intake/exhaust manifolds and ThermoQuad with the factory dual snorkel air cleaner. Car was 727 with factory high stall converter and 3.55 gears. I've also been in a similar weight 5.2 magnum 5 speed pickup. I can attest that Charger was every bit as fast as a '66 390 Fairlane GT-A with headers and some performance mods, the 5.2 ain't even registering on the radar. The five speed 5.9 truck with 4.10 gears I've rode in was quiet a bit better than 5.2, but it ain't even in the same neighborhood as that 340. Closest stock car I've been in that compares to it was an LS ram air firebird, and I would have put my $$$ on the Charger.
 
Last edited:
If you're looking to have a cheap, fun driver, I'd lean to the 5.2 combo, it should be reliable and easy to find parts for and fix if needed, plus if you plan to drive it 12 months of the year in Canada it's likely to more driveable in the cold months. A 340 has the obvious appeal to the Mopar crowd, but at the end of the day it's your car. You stated that it's not a # matching motor, so while the 340 would add value, is it worth the expense to you in terms of enjoyment? I drove a warmed over 318 wtih 340J heads and cast iron intake/thermoquad year round in a 1970 Dart for a couple years in Winnipeg, had tons of fun with it, and very few problems. Keep the 340 and when you grenade the 5.2 or just decide to go that route you have it around.
Just my.02
 
Very true! 318’s make fun and reliable drivers. With good compression and attention to head work they are very strong engines too. Save your 340 for your hot street build. I wish I had one tucked away in a corner somewhere, lol!
 
I have both.....but im sure a rollerized 5.2 and good ported gasket matched intake and heads and dual exhaust could match the power of the stock 340 , i want a cheap on gas high reving reliable small block....a 5.9 is amazing for torque but the 5.2's rev capacity ia greater exactly like he 340
 
The 5.2 would be far cheaper and easier to find. If you keep the stock EFI you'll need find a way to program the ECU if you make any mods. 5 speed depends on the great box. Truck 5 speeds suck. They are typically geared differently and shift like crap. A T5 from a Mustang would good, especially if its a stock 5.2. 300hp/300tq is a pretty fun combo on the street with a light car.
 
Last edited:
Garrett Ellison said:
Son, I've been in a 4300 pound '73 Charger with a 340 rebuilt 340 that was set up with 10.5:1, X heads, MP stock replacement purple shaft. Had a stock '73 iron intake and ThermoQuad with the factory dual snorkel air cleaner. Car was 727 with factory high stall converter and 3.55 gears. I've also been in a similar weight 5.2 magnum 5 speed pickup. I can attest that Charger was every bit as fast as a '66 390 Fairlane GT-A with headers and some performance mods, the 5.2 ain't even registering on the radar. The five speed 5.9 truck with 4.10 gears I've rode in was quiet a bit better than 5.2, but it ain't even in the same neighborhood as that 340. Closest stock car I've been in that compares to it was an LS ram air firebird, and I would have put my $$$ on the Charger.
Click to expand...

I can attest to that as well. You know I've always heard there's "one in every crowd" as far as fast cars from different years and models. I also had a 1973 340 Rally Charger. That car already had a reputation before I got it. All the local LEOs knew the car well. It was stone stock with 79K on the clock when I got it. Had been wrecked twice in the front, but still driveable. That car would outrun everything at school except a 71 LS6 four speed Chevelle, and a 70 Camaro with a really hot small block 400. I had that car with the speedometer in the 7 o'clock position running out I-16 going towards Dublin with six of us in the car. One of the guys asked "hay Rob, will it do 150?" I said "I don't know" and stabbed it. 150 was at "about" 5 o'clock and by the time I got to 7 o'clock, one of the boys was in the floor board bout wizzin all over hisself. We always "figured" about 165 "or so". That car would absolutely fly. Here it is, in all its glory after we put the new front end on it in about 1981. I was probably fixin to put the "super tune" on it for that weekend's festivities. LOL

ME AND CHARGER.jpg
 
RustyRatRod said:
I can attest to that as well. You know I've always heard there's "one in every crowd" as far as fast cars from different years and models. I also had a 1973 340 Rally Charger. That car already had a reputation before I got it. All the local LEOs knew the car well. It was stone stock with 79K on the clock when I got it. Had been wrecked twice in the front, but still driveable. That car would outrun everything at school except a 71 LS6 four speed Chevelle, and a 70 Camaro with a really hot small block 400. I had that car with the speedometer in the 7 o'clock position running out I-16 going towards Dublin with six of us in the car. One of the guys asked "hay Rob, will it do 150?" I said "I don't know" and stabbed it. 150 was at "about" 5 o'clock and by the time I got to 7 o'clock, one of the boys was in the floor board bout wizzin all over hisself. We always "figured" about 165 "or so". That car would absolutely fly. Here it is, in all its glory after we put the new front end on it in about 1981. I was probably fixin to put the "super tune" on it for that weekend's festivities. LOL

View attachment 1715467040
Click to expand...


Had a buddy that had one back around '79, IIRC it had 3:55s in the rear, 340/727 slapstick, green with the laser stripe, gorgeous car, and crazy fast. He blew the motor up at least 3 times before selling it. I got a chance to drive it about 2 years after he sold it, motor was really tired by then, it ended up sitting in that owner's driveway for years after. I tried to buy it at least 10 times, but he wouldn't sell it. Eventually it disappeared, never saw it again.
 
The 318/5.2 is a badly underrated engine. Build it like a 340 and it will respond like a 340.
 
ValerianMagnum said:
I have both.....but im sure a rollerized 5.2 and good ported gasket matched intake and heads and dual exhaust could match the power of the stock 340 ,
Click to expand...
It’ll never happen. Never.
i want a cheap on gas high reving reliable small block....a 5.9 is amazing for torque but the 5.2's rev capacity ia greater exactly like he 340
Click to expand...
The ability to rev high is not it the shorter stroke of the 318 vs the 360 but in the cam, valve springs, as well as the ability to breath in and out.

A 5.2 is a good option for the description given. With making use of the stock heads...
You’ll need a Magnum engine RPM intake, carb and a LA styled distributor. Chose a cam that fits the intended drivetrain. A ported head will allow for more useable rpm’s up top.

kesteb said:
The 318/5.2 is a badly underrated engine. Build it like a 340 and it will respond like a 340.
Click to expand...
But it will never be a 340 or perform as well as one.
The 318/5.2 is still a good option to tool around with or leave stock for mileage purposes. But it’ll never out do the 340.
 
take off your 20% gross to net conversion and your 340 is now at 240 HP!

however, the larger bore/oversquare adds torque

the real difference is the poor/truck splits in the 5 speed trans (either AX15 or NV3500)

the 833 wins that easy
 
Thinking about goung 5.2 with a holley sniper kit and a mustang t5 trans and like 3.55 or 3.91s , camshaft and light ported heads , hands down that this 5.2 can beat any 340 or 340 6 pack....i love the 340s but i even rather buy another 5.9 than restore an old v belt and flat tappet / high compression and rare engine....cheap , reliable and streetable fun is what i want . 5.2 and 5.9 are all over the world and have so much potential , of course i dont need 500hp
 
ValerianMagnum said:
Thinking about goung 5.2 with a holley sniper kit and a mustang t5 trans and like 3.55 or 3.91s , camshaft and light ported heads
Click to expand...
That would be a fun and inexpensive set up.
, hands down that this 5.2 can beat any 340 or 340 6 pack....
Click to expand...
You are smoking some crazy stuff! Please pass it on.
i love the 340s but i even rather buy another 5.9 than restore an old v belt and flat tappet / high compression and rare engine....cheap , reliable and streetable fun is what i want . 5.2 and 5.9 are all over the world and have so much potential , of course i dont need 500hp
Click to expand...
Did a 5.9 in my last ride. EZ-PZ!
 
U say u want mileage , but yet ur going with 3.55s or 3.91s. Then for sure u need the od tranny. But ur still in a dream world with ur lil 318 if u think ur even gonna be close to a 340 or 360/5.9. Kim
 
oldkimmer said:
U say u want mileage , but yet ur going with 3.55s or 3.91s. Then for sure u need the od tranny. But ur still in a dream world with ur lil 318 if u think ur even gonna be close to a 340 or 360/5.9. Kim
Click to expand...
I don't think it's a dream, 5.2 has bunch of potential everyone always writes these off .
 
5.2 magnum not old 318 2bbl , and a t5 wclass trans ( fox body ) with a cam and holley sniper efi , ill put my money on the little magnum, pretty sure you cant beat the technology bump...the 5.9 kills the 340 already , 400hp and 440 of torque with a 4bbl and a camshaft + headers ( stock rotating and stock heads not even removed from the block 8.9:1 compression ) ...the 340 needs roller rockers , high compression ratios , big camshaft and good bowl porting job / gasket match , good ignition , bla bla bla ...****so why a 5.2 with the same good stuff than a 340 can beat it ? Because of its legendary status...comenon guys , its like comparing the newer hemis vs the old hemis and the 350 vs the ls....
 
And I like a 318 a lot, run one myself with 10:1 and 222/232 @ .050. It's a happy combination. But anything done to wake a 318 up does exponentially more so in a 340. Developed from it's inception as a performance engine by Tom Hoover on a clean sheet of paper, all the years of knowledge gained in sonic tuning, airflow, and very important, production casting high strength production blocks came together. The 318s that come closest to being able to make 340 performance are the H.D. truck blocks and 318-3 and I read some speculation/conjecture on 318-1 3 Motorhome being a service replacement block that were cored on 340 castings with high nickel alloy content iron. Most of these blocks can actually be bored out to 340 size anyway
 
Ok, let’s do the 5.2. The other old tired iron is out to pasture. Do a good rebuild on the 5.2 and call it a day. The fi is a good call. Get a good clutch. Use synthetic fluids. Lighten the car. Make sure the brakes are not dragging. Good wheel alignment helps to. Keep tires inflated to proper psi. Kim
 
You must log in or register to reply here.
-

Back
Top