Base timing on a 1977 K10?
 

Truck is a heavy half 77 k10. Has factory 350 with the 4bbi. Truck came factory with No emissions equipment what so ever...So it has no EGR, no cat ect...

What is the timing supposed to be set at initial? Been seeing all different readings online any where from 4-8. My decal is long gone so that is not gonna help. Truck runs okay but seems to have trouble when snapping the throttle or even when using larger amounts of pedal. Would timing being retarded have any effect on this? It has even puffed White smoke and died a few times indicating it flooded out.


So what is the timing supposed to be set at on a 1977 350 4 barrel non emission motor?

Thanks

Re: Base timing on a 1977 K10?
 

My non-emission 350-4bbl in my 78 3/4 ton is supposed to be set at 8 degrees.

Re: Base timing on a 1977 K10?
 

84, spec is 8 deg, BUT, there are alot of things going on and there is room to alter this setting. We all know the higher you can safely run the timing the better performance and fuel economy get. That being said, check the distributor and make sure the vac advance is working properly and the fly weights are free to move against thier springs. Don't worry about changing weights or springs (recurving the distributor) unless they are broken or missing. Base timing is set with the vac advance disconnected from it's vac supply. The vac supply is full time manifold vacuum. Set your base timing at 10 degrees, hook the vac back up and test drive it as you would normally drive it. Does it ping? If it does, drop it back to 8 degrees. (if it pings at 8, your running to lean a mixture) If it doesn't ping, bring it up to 12 degrees and do the same thing. Mine is an 84 3\4 ton 4 speed stick 350. Mine is supposed to be 8 degrees also, but it is set at 12 and doesn't ping unless I really lay into the gas without downshifting. I get 17 mpg up from 12 when set to 8 degrees running on reg gas. I think I could jack it up to 14 degrees if I ran premium gas and get over 20 mpg, but I don't think it would be cost effective as premium gas costs 30 cents a gallon more than reg. jim

Re: Base timing on a 1977 K10?
 

78, Thanks for the info.

Jim, Thanks alot very helpful post. It was running at 5 initial timing so I bumped it up to 9 and had to turn the idle down a bit back to the factory 700. Seems to have a bit better power. I think it could handle 12 but i got a big 4x4 trip tomorrow and don't wanna play with it to much. Still stumbles if you floor it but that probably has more to do with the carb then the timing. It does seem more responsive and does not stumble as bad.

Thanks again for the info guys

Re: Base timing on a 1977 K10?
 

Rule of thumb on the older vehicles was to add 4 degrees to the timing. If it was at 8 bump to 12. Got a bit more power and if your lucky a bit of mileage.

Re: Base timing on a 1977 K10?
 

Strangely enough, I have no idea what my timing is set at. All I know is it starts fine, runs good, and doesn't ping unless it's loaded pretty hard. I might be leaving a little on the table. But I figure I'd spend a lot of money on a dyno trying to get it. So, it is what it is. Tuned by ear.

Re: Base timing on a 1977 K10?
 

Well if you can get it to ping under load then you are maxed out, should even bump it down a tad, pinging is very bad!