spark plugs, wires, coils and DSII on 250

bmbm40

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I recently completed a 250 install for my 66 Bronco. The 250 is from a 1970 Mustang all stock and the PO did or had a valve job done. It starts up and runs fine with the Carter carb. My friend did most of the work on the DSII from the pic and pull and the timing is set to stock as well as plug gap. I am using the module, plug wires and coil from the donor vehicle for DSII, they look ok but when cruising at any constant speed I get an occasional miss, very brief and one day during some extended wet weather had a noticable miss under hard acceleration so probably plug wires need replacing. Will check on a moonless night just to make sure. I am learning confirm everything I can.
So I want to replace the plugs and open the gap a bit and advance the timing a little.
Also want to modify the DSII for faster advance.
A friend has a Jacobs coil and some spiral core wires, Accel I think he said that he used for about a year before he put a v8 in his Bronco that I can get real cheap like $40.
Did some research of past forums and the Autolite ap46 and app46 and ngk 7510 seem well regarded and I beleive these are extended tip plugs. I had looked at some of those Bosch plugs with two electrodes because I considered indexing my plugs. Is indexing going to yield any appreciable difference with what I have?
Also does this seem like about the best ignition system I could have for the money. I plan to carry a spare DSII, coil and module with me for offroad emergencies so that pretty much excludes DUI and MSD ignition from a financial perspective.
Looking to get the most performance out of what I have until I can get another head and mill for 2100, 3 angle, port and polish etc.
Thanks for everyones help so far, this site is great for six cylinder junkies. Also the Falcon manual, I am constantly looking at that. I still just get polite blank stares from my friends when talking about modding Ford sixes.
I appreciate any and all input.
 
Howdy Back Bm:

What is your elevation where you are running? A wet weather miss sure sounds like some sort of short issure. Are your friend's Accel plug wires custom for a Ford six? If so that would sure be an improvement over 38 year old carbon core wires. Also check the inside of the distributor cap for carbon tracking. It is caused by the fine dust inside the cap forming a track to leak electricity.

As for plugs, buy whatever is on sale in the aproximate heat range and check them often. Your engine will tell you what heat range and brand it likes best. I swear by Champions in my 250. Others swear at them. Autolites are frequently on sale. I use them too. I use a colder heat range in summer driving and hotter in winter. Indexing will not make a significant difference in normal daily driving. I've been doing it so long I can't quit it. Depending on your elevation, engine vacuum and cam you will be able to use about 5 degrees more initial then stock specs call for. I use 16 BTC, with a Comp 260 and @ 5,000 ft. elevation.

If you get your DSII centrifugal avance modified to come in sooner you will have a very solid and reliable ignition.

I think I hit all your high points. enjoy!

Adios, David
 
I am about 4300 for elevation. Yes the Accel wires are custom fit, spiral wound used less than a year. Thanks for the tip on the distributor cap I may replace it just to be sure. Also on my list is a DSII with the centrifugal advance mod, planning to pick one up at picnpull or a rebuilt from Napa to mod then swap it with my current DSII and keep that as a spare in the vehicle. I notice alot of people are using the GM module. Is there a noticable performance increase with these?
Thanks for your help
David
 
I am about 4300 for elevation. Yes the Accel wires are custom fit, spiral wound used less than a year. Thanks for the tip on the distributor cap I may replace it just to be sure. Also on my list is a DSII with the centrifugal advance mod, planning to pick one up at picnpull or a rebuilt from Napa to mod then swap it with my current DSII and keep that as a spare in the vehicle. I notice alot of people are using the GM module. Is there a noticable performance increase with these?
Thanks for your help
David
 
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