Jeff: check to ensure you are applying the proper Balance weights. Post 71's use an external balance which means off set weights on the converter. Ask Hughes what they recommend. You may want to check for alignment of the trans case to the block. Small blocks are notorious for core shift. I had...
68-69 should have a p/n or casting # of 2531914 or 2531915
70 would be 3512847/3512848
71 (spread bore) is 3512099/3512100
72 is 3671878
hope this helps.
I'm looking at the square bore for a 71 340 which is in my dart
the spread bore is to go on my 78 LRT
Your bottom line???
If 1/4 miling, go for the 360 with the 340 cam from 68-71. Put on the 340 heads, which will need the 340/360 valve springs and rockers. I did a similar set up and used a 360 2bbl manifold and 71 360 carb. Got 18mpg and a good street performer.
Back in my "usta days, I built up a 318 for my son's 73 duster: used 360 heads and 360 2 BBl manifold and a holley oem 2 BBL carb: great mileage and able to use all the original linkage, choke connects etc. The bigger ports in the manifold and heads really made the 318 liven up!
71 dart with 318, PS and AC. removed worn out pitman arm and replacement (Moog 7074) will NOT work as its splined hole is 1/8" too small to fit on steering box shaft. I know Ma mopar had 2 different sized sector shafts and I may be in that mixip. Any one out there have a solution or Part #? I...
Find true TDC via #1 cyl, without looking at the damper. simple yes/no and you know the problem, and the fix.
use PORTED vacuun only for dist. timing
Once that is set, I'd go for 850-900 rpm initial, with your cam profile!