[Mini Cobra]

I am helping on a 72 Chevelle restoration, and I am having problems identifing the engine. It was told that it was a truck 350, but the engine number doesn't come up anywhere. The nunber on the front lip is CE7P27S05. The motor was extremely advanced when I first looked at it. I took it to the 4 degrees BTDC and the motor ran smoothly being warm. After it cooled off, starting it causes it to backfire through the carb. From 67 to the 80's, 4 to 8 degrees btdc for a 350 is standard. I have found one truck motor setting though with manual transmission set at TDC. Can anyone help with identifing what motor is in this beast?

[DoubleVision]

CE indicates it was a replacement engine under warrenty. What`s the casting numbers? The casting number is on the drivers side rear of the block.
Since it`s a 72 chevelle, it`s possible the original engine died for a various reason so GM installed a replacement engine or somebody did a engine swap and this was the engine it ended up with. Give us the casting numbers and we can tell you what engine you have.

[Mini Cobra]

I finallly had time to get the casting number It is 3959512.

Thank you for your help.

Mini Cobra

[techinspector1]

3959512....327...62-67...2...Was also used for some "CE" replacement blocks
So it's a small journal 327 2-bolt main block.

[Mini Cobra]

Now that I know it is a 67 327, the HEI distributor is definitely an upgrade. What kind of timing problems should I be expecting?

[DoubleVision]

First thing to do since it`s popping back through the carb is check it`s getting 12 volts or more to the HEI all the time when the vehicle is running, Anything less will result in spitting and backfiring. Next thing make sure you have the firing order correct. Next is check it for vacuum leaks. The timing should be 12 degrees before top dead center with vac advance disconnected and plugged. After setting the base timing reconnect the vacuum advance to a full time manifold vacuum source, one that pulls vacuum full time including idle. If you`ve checked all the bases and it continues to pop through the carb it`s quite possible the cam is worn. Did the car sit for a extended period of time? To check the cam pop the valve covers and watch the rocker arms, if you see one or more barely moving compared to the rest then the cam is history.

[starnest]

DoubleVision is right. And the first check is important.

Before HEI came along, GM used a resistor wire in the ignition feed to the coil that dropped the voltage from 12 VDC to about 8 VDC. This was done to reduce the burn rate on the points (contacts). During start (while the starter is engaged) the resistor wire is bypassed, providing full 12VDC to help with starting.

In most cases the HEI won't work at 8VDC, but sometimes it does (I've never seen it work at 8VDC), and I'd expect that it messes up the timing.

Just a note, the ignition wire needs to be connected to a load when you measure it. If not - it will measure 12VDC (floats to source voltage) and drops to 8VDC when connected to a load. The expected load is an ignition coil (about 3 or 4 ohms) with the negative side connected to ground.