[GLHS60]

The 340 was definitely under rated at 275 H.P.

An interesting thing is Chevy built a specific 1969 LM1 combination to compete against it in NHRA.

The 1969 LM1 was a 350 4 bbl under rated at 255 H.P. and is still competitive today.

1969 Nova and Camaro SS models had the 300 H.P. version as standard equipment.

Only lighter non SS cars got the 1969 LM1 package to compete against the light 340 Darts etc.

LM1 cars got Muncie 4 speed trans rather than the Saginaw normally used in cars less than 300 H.P.

Most also received 12 bolt rears instead on the 10 bolt units found in non SS cars.

The 1969 LM1 was discontinued after about Feb 1969 and was replaced by the 350 2 bbl. 250 H.P.

Interesting history!!

Thanks
Randy

 

[MPE426HEMI]

My favorite sounding engine.

 

[CudaPete]

Big valves, big ports, high revs! Really pulls at the high end.

 

[Fast Eddie]

The 340 was definitely under rated at 275 H.P.

An interesting thing is Chevy built a specific 1969 LM1 combination to compete against it in NHRA.

The 1969 LM1 was a 350 4 bbl under rated at 255 H.P. and is still competitive today.

1969 Nova and Camaro SS models had the 300 H.P. version as standard equipment.

Only lighter non SS cars got the 1969 LM1 package to compete against the light 340 Darts etc.

LM1 cars got Muncie 4 speed trans rather than the Saginaw normally used in cars less than 300 H.P.

Most also received 12 bolt rears instead on the 10 bolt units found in non SS cars.

The 1969 LM1 was discontinued after about Feb 1969 and was replaced by the 350 2 bbl. 250 H.P.

Interesting history!!

Thanks
Randy

I did some of the original dyno development on the 340 when I was running the dynos at Chrysler. The 4 bbl 340 running under lab gross conditions (no air cleaner, deep sump pan, max spark and F/A, cold intake manifold, no accessories, and lab exhaust) would make in the range of 320 to 330 HP at 6000 rpm. The 275 HP advertised number was for NHRA Stock classificationn to make it more competitive.

 

[GLHS60]

Thanks for sharing your vast knowledge and experiences!!

Coincidently, I believe NHRA factors the 340 at approx. 320 H.P.

Thanks
Randy

 

[pt006]

The 340 six pack would have had even more power if they added a little more to the mold to eliminate the pushrod bulge in the intake port. And maybe a little bit more cam. 340's made a lot of power without spending a lot of money.

 

[rapidtrans]

I remember the car mags questioning the 275 hp rating. Most estimated a stock 340 pumped out over 300. Some thought the lower advertised rating might be for insurance purposes. A 70 340 Duster embarrassed many Ford and GM muscle cars.

 

[MPE426HEMI]

The truth behind the 340, is that it’s awesome!

 

[Doug D]

In HS I remember I really liked the 340 Duster. Would have loved to have had one.

 

[MPE426HEMI]

Ahhhh.....

 

[Glopart]

Had a 70 , 340 , 4 speed Duster in the early 70's. Stomped my friend's 350, 4 speed Nova easily. When I would hit second gear really hard the passenger door window would pop out of the rubber at the top. Wish I still had it.

 

[dodgeismycar]

My first car was a 1969 B-5 Dart Swinger 340 4 speed. It would romp all over 396, my buddies 489 Cobra Jet. I took it the Dodge dealer in Binghamton, NY and asked me where I purchased the car Why I asked and the service manager responded that the car had canted heads, which I did not know what that term meant. Was he telling the truth?? I LOVED that car and did find another in Raleigh exactly like mine but no deal could be made on his car (sigh)

 

[rapidtrans]

Ahhhh.....
View attachment 11091

Another of Dad’s grilles.

 

[MPE426HEMI]

Another of Dad’s grilles.

Lucky you!!!!
Love that grill!

 

[Shane Estabrooks]

So .. in the 80's I had 70ish dodge dart .. my gear head freind at that time said it was a 318 wide block... I'm not sure.
But that car was not slow.. I can say

 

[Fast Eddie]

The 340 six pack would have had even more power if they added a little more to the mold to eliminate the pushrod bulge in the intake port. And maybe a little bit more cam. 340's made a lot of power without spending a lot of money.

There was no real manifold development for the 6-pack. .................

 

[rapidtrans]

So .. in the 80's I had 70ish dodge dart .. my gear head freind at that time said it was a 318 wide block... I'm not sure.
But that car was not slow.. I can say

A 318 in an "A" body was a nice running car.
Don't know what they meant by "wide block".
318, 340 and 360 were small blocks based on the 273 since maybe the 67 model year..

 

[Shane Estabrooks]

A 318 in an "A" body was a nice running car.
Don't know what they meant by "wide block".
318, 340 and 360 were small blocks based on the 273 since maybe the 67 model year..

Ya knowing what I know now.. It was just a 318 sb, but I think at that time my gearhead friend was saying that because of the "look" of the intake.
Wish I still had that car... so much fun was had. When I look back I've owned a lot of 318s .. wish I could say that I've had a 340.

 

[dodge4x4]

I'm not an expert on the 340, did have one in my 72 Cuda though. What I remember when they came out was that they revved up fast and were quick, which is the reason they performed so well. But then again that was what, 50 years ago? I have had a couple slant 6s, a couple 273s, the old style (50s) 318, several newer 318s, the 340, but don't remember having a 360. Also a flat head 6, 325 hemi, 392, and I think something like a 351 but not sure. And of course several of the newer engines. Had a couple 3.5L 6s, they are really good engines except you have to replace the timing belt every 100,000 miles. Now I drive mostly my 05 1500 with the 3.6L 6 (I think that's what it is) and my 05 3500 5.9L diesel.