X head question

[73blueduster]

I have a 1968 340 with X heads (2.02/1.60). I was wondering if anyone knew what the horsepower and torque specs where on that kind of engine, Im 17 years old and very new in the mopar scene and I would just like to know what im working with.

Your feedback is appreciated!!!!.........Joe

[Madman Stephan]

Hi, in order to make a "guess-timate" there's a few more things we need to know:

Is this engine bored?
Does it have headers?
Aluminium or cast iron intake?
What size of carburator?
Original cam, if not, specs?

With just the information you provided, the HP numbers could be anywhere between 240 - 600 HP's....

[TK]

stock, I think it was 275hp
and 340 pounds of torque.

[73blueduster]

My 340 has headers, aluminum intake,stock cam, its bored .30 over,with a holley 670, other than that, it is all stock.


Thanks....Joe

[coupe32]

Dodgetruckboy is right. The 68 340 was supposed to be 275H 340 ft. pounds torque. Some people thought it developed a little more HP than was advertised.

[Stoga]

Originally Posted by 73blueduster

My 340 has headers, aluminum intake,stock cam, its bored .30 over,with a holley 670, other than that, it is all stock.

It should be right at, if not just a bit over 300 hp, assuming everything is in good shape and top notch tune.
If you dont mind me asking, do you still have the car that motor came in originally? While not Hemis or 6-Barrel 440s, original 340 cars are getting quite collectible these days. If you ever get tired of it, I'm sure there's a person out there with a Dart, Duster or Demon who'd just LOVE to take it off your hands!!

[Tarrbabe]

But NHRA re-rated it for drag racing. I don't remember exactly but they rated it at about 305 to 325. Maybe someone else remembers what it was.

[Dart 65]

Yes, the 340 had 275 horses and 340 ft lbs @ 3,200 RPM from '68-'71. CR was 10.5:1. From then on, it had 240/290 with 8.5:1. Were they underated? Like all engines of the era, it was underrated by as much as 15%. That was to trick the insurance companies.

[73blueduster]

Stoga, i bought the engine and car seperatley.

[Scatman 340]

Originally Posted by Tarrbabe

But NHRA re-rated it for drag racing. I don't remember exactly but they rated it at about 305 to 325. Maybe someone else remembers what it was.

In 1968 the NHRA factored the 340 at 310 HP to run in D Stock.

[345Dart]

I sold a basic rebuilt 340 a few months ago with a cam upgrade from what you have and it dynoed @ 387hp @ 5800rpm with 410lbs torque @4200.

If you want to make a few changes/upgrades to get 400 hp send me an email. leo.givens@fluor.com or I'll be at Mission raceway in a gold coloured 68Dart for the Loafers oldies meet on July 30-31st along with 250-300 others.
Bring the Duster over for some fun and help beat them Fords and chevys.