timing question..???

[1971scamp383]

hi all....ive just tried to put the timing light on my 383 and man....i just cant do it right!!!!...first ive locked my vacuum advance...then put the timing light on and timed it to 36 degree at 3000 rpm.....man the car just wont idle...when i stomp the gas ...it feels like it as no power at all.......and stalls!!!what im i doing wrong???....so i just put the timing where it seems to idle fine and start fine....and man.....the car feels pretty good til 4500 rpm....at 4500 rpm when in first gear.....it starts to back fire in the exhaust.....i cant run over 4500 rpm......why??...the car  have a way better launch then before but its not timed correctly and back fire at 4000 4500...can you guys help me  please??? thanks a lot....ohhh yeah....also....if a guy    turn the screw backward(vacuum advance)to much ... can it be bad??? it just turn correctly now (i have tighted it until it stops...(locked it) )but a mechanic guy  just wanted to see what it does when the screw was full open...so maybe he just slack something in the dizzy???

again here is the build....383 .030 over...stock forged crank polish and new bearing....edelbrock double roller timming chain...edelbrock torquer aluminium intake(i know ...but hood clearance issue but not clearing with the spacer anyway )....2'' 4 holes phelonic carb spacer.....comp cams xe274.....edelbrock 750 cfm performer series....mopar performance distributor kit with orange box....taylor 8mm plugs wires....full length hedman headers 1 3/4 ..3'' out....440source aluminium heads(2.14 1.81 )....keith black dome pistons..(6cc dome)...10.1cr right now.....2500 torque stall(stall at 2900 rpm)...freshly rebuilt 727 with b&m transkit(shift kit)...3.91 rear gear with locker lock right)

[satellite65]

When you say you set the advance to 36* @ 3000 rpm did you do it with the vacuum advance hose disconnected? When you dropped the idle back to 800 or so what is the initial timing? Backfiring through the exhaust is usually an indication of late timing. Could also be a valve issue.

[1971scamp383]

if ive locked the vacuum advance...do i need to unplug the hose???and the initial timing i think was around 18-19 if i remember correctly...thanks...

[satellite65]

I don't know if you actually "locked" the advance by doing that. You may have just limited how much it will advance. By disconnecting the hose (and plugging it) you disable the vac adv and take it out of the picture completely. 18-19 doesn't sound unreasonable but do it with the vac hose disconnected.

[bOb shingler]

the slots in your distributor too long. meaning it will over advance at the correct idle setting and not have enough advance at the 3000rpm setting. what will correct this is to remove the advance plate and weld inside of the slots, nearer to the center. weld it about an 1/8" then file them so the slots are the same length. this will give you what your looking for. good advance at 3000rpm and will idle at about 19*, if the idle won't come back far enough file the slots more and try it again until your happy.

[ksdartguy]

The mopar dizzy's have an adjustable plate on the mechanical advance.
You can limit the mechanical advance without welding.

You need to know that your total timing is around 36.
If you have heavy springs, you might be running more timing than you want,

Rick

[moparbubba]

I was told most mopar distrubitors have 22 degrees centrifical advanse. Disconnect the vacuum advanse and plug it. Set your timing at 14 degrees and road test the car. If it runs good, the problem is in the vaccume advance. Also make sure the vaccume advance is not hooked to manifold vaccume.