I just rebuilt my 350 small block. and the advanced timing only moves around 8 to 10 degrees.. and my truck runs kinda sluggish. dont know what to do. this engine does have a step up cam in it. and new distrubutor and wires and plugs.

back firing through the carby is an indication of valve timing, bad valves, ignition timing or crossed HT leads. Check the firing order

It may have to do w that timing chain due to vacuum advance being off too.

Sounds more like you have a valve problem, have you looked closer at this problem

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You paint or chalk the crank damper grouve first

Then you disconnect & plug the dist vacuum hose

Then you will see the grouve move up on the timing
tab as you turn the dist

Your setting the initial timing,not 34 on the tab

Don't forget the cam turns twice as fast as the crank
& thus the dist & then you add vacuum advance

Your setting the timing somewhere around 8 to 12 degrees
The correct setting should be on the radiator support

If the motor is in something different & you have an advance
timing light ,you can put 34 in the light & adjust the grouve
to O degrees on tab

around 4-6 degrees before top dead center / BTDC to start,then you can set it for more if you need to smooth out the idle.On my 74 350 i didnt go more than 10-13.idle should be at around 700 rpm's.So if 4-6 makes it to low then advance it till it hits 700 rpm.

Ok,What you will need is called a timing tape. It is a piece of tape with timing degrees all the way around it and you install on your balancer so you can read the advance.This can be purchased from any perfomance store. just line up tdc on balancer with tdc mark on tape and wrap around your clean balancer. the other option is find someone with a timing light that will measure the advance.most higher grade lights will have an advance button that you push until Tdc is showing at timing marks and then you rread the advance on light.

the coil will get hot with running ,timing must be out put cam back as it should be ,it will not run any better with the cam advanced ,this is tech talk by part time weekend mechanics that know sweet all nothing .reset the timing to static for number one TDC ,firing order 153624 ,the only way a cam will give more rpm is if its designed to with a different cam lobe configuration not just moving it ,This will also cause the engine to use more petrol because it has no power at the low RPM range .These boy racer mags think they know it all with their cog boxes and harry moss add on goodies ,and fancy paint jobs .If you want a faster car get a ferrari or a jaguar XK ,and ignore these so called experts who are all talk to baffle people like you ,if they think they know it all just ask this question ?? is this engine adiabitic or isothermal ,if they cannot or will not answer this question then just call them a sunday mechanic .

You can set the timing but the ecm, engine control module will reset it back to specs. So it useless to try. Good luck dont forget to rate

check the throttle pos sens

If the ECM is still in and working, "0" deg unplugged would be correct. But are the timing marks correct? If the marks are lined up statically on "0" deg. is the #1 piston at TDC? Also important is for the ECM to be happy with the feedback it gets from it's sensors so it is running "in loop" If the "check engine" light is on, it will run but poorly. Make sure all sensors are in place and connected properly.