340 tune specs

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ramvan3

ramvan3

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Looking for the correct tune up specs for a 1972 340 engine external balance ( ignition timing, spark plug type, gap, etc. Motor is a 340 with 4 bbl, 4 speed, power steering, no power brakes. Ignition is converted to electronic with a mopar conversion kit.
 
With vacuum advance unhooked try 13 BTDC at idle for the timing. Plug gap is .035". You can go to rockauto.com and look up the plugs. I prefer Autolite brand spark plugs. They work great and are cheap. A lot of Walmarts have them too. Stay away from Champions and the more glitzy plugs won't buy you anything.
 
340sFastback said:
With vacuum advance unhooked try 13 BTDC at idle for the timing. Plug gap is .035". You can go to rockauto.com and look up the plugs. I prefer Autolite brand spark plugs. They work great and are cheap. A lot of Walmarts have them too. Stay away from Champions and the more glitzy plugs won't buy you anything.
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It just crazy all the different stories flying around. Back in the day Everyone always said use ONLY Champion plugs in Mopar. They were OE Plugs and always ran great for me. The along came Autolite and everyone said they were the Co. that Made Champion(or Visa Versa). I always used Champions in My Cuda 340 and it ran great. Same in my Cuda 360. The A/L's also ran great. Now I hear this and It just blows my mind. Not trying to bust balls but Id like to see some proof that A/L's are good and Champions aren't.
 
I agree I run champion and never had a problem, Im trying E3 right now because a guy gave me a set for free. They seam to be ok also.
 
The original factory spark plugs for the 3.3L/3.8L minivan engine will fit and work well also. They are champion platinum plugs. They were put in the minivan engines because the rear bank plugs were difficult to change, so they used a platinum 100,000 mile plug in them.

They changed the spark plugs for the 2001 3.3L/3.8L engine and later to a tapered seat and no gasket. Those will not work. Only the pre 2000 and earlier plugs will interchange on the small block. I've been using these for years with no problems.
 
factory specs for 72 340
ignition timing 2 1/2 btdc
spark plug [email protected] 340 had electronic igition in 72 so no dwell or gap specs
idle speed manual trans 900 cali only all others 750. auto 750 in neutral
 
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