Timing?

[348NUT]

I got my 56/350 back on the road after having to change heads because of a crack. I put on a set of small valve heads and I have about 9:1 compression. My question is what should I set the timing at for the best gas mileage? Should I be more concerned about the initial or advanced timing? I have to buy a timing light so should I pay the extra for an advance light? Any place I can get a good one at a good price? I should mention I'm running a quadrajet, 1700 rpms @ 55 mph. I could have asked this over at Chevy Talk but I just feel so much more at home over here! :D Thanks, NUT

[348NUT]

I should also mention It has a stock cam and the original 265 single exhaust. It had 1.94 intakes before and it got 17-18 mpg at 60-70 mph on the freeway. I better watch what I say, I could get kicked off of the High Performance Web Site! ;)

[IgnitionMan]

You would want 10 to 12 degrees of initial timing, adding another 8 with the vacuum advance on full manifold vacuum sourcing. This will give you 18 to 20 idle degrees after the engine starts.

Total timing would be 34 to 36 degrees, so, the mechanical would have to be 24 to 26 degrees, starting at 100 rpms after out of geqar idle speed, limiting about 3,000 rpms.

Doing the vacuum advance this way will require a stop to limi9t its degrees. E/mail me via regular off board e/mail and I will send pics of one you can ewasily make and fit to your vacuum advance cannister. Somehow, some web sites don't haver the e/mail option that connects e/mail directly, have to go through the board's server, and pics aren't easily attached/sent.

Don't know if this new board is easily e/mail w/picture worked, but regular e/mail is easy.

[bobs409]

No problem posting this here 348nut. Your a member, you own a 348 and your posting an off topic question in the general/off topic area. Well done I'd say! ;)

Ignitionman, our file attachment works good here. (as long as it's not too big as there is a limit) We have Private messages too but I haven't tried them out yet. When you send a PM, the person should recieve a notice in their regular e-mail telling them it's there. But anyway, feel free to post pictures for reference purposes like these as that's what it's there for. This way we all get to see! :D LOL

[IgnitionMan]

I have absolutely no idea how to post a picture or work it through the board e/mail system. I do it all the time on the reply and/or new e/mail on my regular stuff, so I just ask people to send me a personal e/mail on my regular e/mail account and go from there.

One day, I'll figure it all out, but for now, full on don't get how to do it. Until then, dq409 owes me big time for getting his paint right, and he knows how to post pics!

Bob, this new board is GREAT!!!!