Hi from the Dancing Wolf

[dancinwulf]

I have a 1970 Duster I restored from a frame body donation it took 6 years to find everything the motor I put in it was 318 stock but it doesn't have a lot of juice I found a 73 340 that I am going to rebuild also have a set of 302 heads I was going to put on it or should I stay with the stock 340 heads and what about cams want to keep it as a driver but would love to have a little more power I understand they backed off the power in 73 as apposed to 1970 340 any suggestions?:

 

[71340Duster]

Hello and welcome to FABO. Any pics of your ride? You might try going to the "small block Mopar engine" section of the forum to ask your questions, there's a lot more views there, this is the place to introduce yourself. I'm building a 340 with Magnum heads, it's high compression (68 block) so I will have challenges. Again, we like pictures here and Welcome!

 

[clhyer]

Welcome aboard Wulf,
C

 

[Keith Mopar]

Welcome to FABO dancinwulf , yea the later 340's lost a little compression in the last years but is doesn't take much to bring them up to good hp levels.

 

[Abodybomber]

Welcome,Wulfie.

 

[70aarcuda]

I have a 1970 Duster I restored from a frame body donation it took 6 years to find everything the motor I put in it was 318 stock but it doesn't have a lot of juice I found a 73 340 that I am going to rebuild also have a set of 302 heads I was going to put on it or should I stay with the stock 340 heads and what about cams want to keep it as a driver but would love to have a little more power I understand they backed off the power in 73 as apposed to 1970 340 any suggestions?:

you dont want 318 heads which the 302 heads are on a 340....you will be choking the engine ...

if you are rebuilding the 73 340...buy the 68-71 pistons to bring the compression up to the earlier years...actually you probably want to be around 9.5 to 1 with cast iron heads...

 

[Captainkirk]

Differences on the '72 and later 340's (nutshell version)
1) flat-top lower compression (8.5:1) as opposed to earlier 10.5:1
2) J-heads with 1.88 intakes as opposed to early J-heads and X-Heads utilizing 2.02 intakes
3) Cast crank, externally balanced damper and flywheel
4) 68-70 340's used Carter AVS carb, 71 and later used the Carter ThermoQuad
5) '68 340's had hotter factory cams than later years.
6) Water pump inlet and timing marks swapped sides in '72.
Basically these are the major changes...easily rectifiable with a mild engine build

Welcome aboard! Don't hesitate to ask any more questions, happy to help!