258 Static advance - How much?

I'm getting my 72 back together and had to re time the engine because I messed with the distributor. The book says 3 degrees but in my studies of the forum I see a lot more advance being dialed in. I don't see a definitive number stated a "the" best advance. The engine runs great with 3 degrees though I haven't driven it (no seats) but I thought I'd ask, you never know, a few more degrees might get me up to 12.5 mpg. Any recommendations for a good place to start if we don't want to believe the design specifications.

 

I originally did the 3 degrees when I had the point distributor in.
When I retrofitted a later duraspark, I went with 8 degrees as was recommended in other discussions around the web.
I believe that the duraspark module retards the timing while cranking.
Runs fantastic with the duraspark and 8 degrees BTDC

 

Thanks for the response. It looks like the engine can handle a few more degrees with points and a few more with the Duraspark. I'm very interested in your Duraspark upgrade. I found your thread about it and think it's the next thing I do to the rig. Any more information to share since you've run it for a while? It looks like the price/performance ratio will work with my (my wife's) budget. For now I think I'll just add a degree at a time and see how it drives.

 

Nothing new to report. It is just the cat's meow,set it and forget it!
Maybe some day I'll upgrade to the CDI type coil but I had already bought a stock replacement coil and it runs just fine.

 

I found 12 to be the sweet spot for me.

 

Now that's what I was looking for 73cj5. I see in you sig that you have a a FI 258, is that fuel injected? If so, I wonder what effect that has on the timing? When I checked mine before I moved it to 3 degrees the mark was off the scale (advanced), way beyond 12 degrees which I think is the highest mark on my scale. Surprisingly the engine started easily and ran pretty well. Anyway, changing the timing is easy so I'll keep advancing it some as I drive it and see what works best. At least I know the 12 degrees is usable for someone.

 

What is the age/condition of your timing chain?
Mine was so loose it was rubbing through the timing cover. I installed a new gear and chain set along with a later cover/balancer when converting to a delco alternator.
There is also a possibility of a slipped timing mark on the balancer.

 

Pete,
The 12 degree number came from when I had a carb. I also ran a hei with an adjustable advance kit. Advance it till it pings and pull it back some. It really made a big difference in drivability and a bump in mileage.

With the EFI I am running 12 at idle , and up to 42 degrees under certain conditions. But I also use the automatic timing redard with a knock sensor to keep things safe.

 

More useful info. I assume that the timing gear is original as I don't see any evidence of repairs. I'm not having any problems and the rig is driveable at least at slow speeds. I took it for a spin around the neighborhood sitting on a box since the seats are taking forever to be returned from the upholstery shop. What is it with upholstery shops!!!. Anyway, I need more wheel time in real world conditions to see what's going on (if anything).

BTW DRED, I saw some costs you had posted for your swap somewhere, could you post those again?

 

re-man distributor (p/n 48-4691) $65.99
ignition cotrol module (p/n TP40SB) $31.99 ​

 

What service. Thanks