As title says I replaced head gaskets on a 307 set timing marks on 0 on compression stroke an wont start I did delete smog pump an AC compressor acts out of time back fires out carb have reset distributor over an over have tried it 180 an back have advanced plug wires have devanced plug wires still wont start acts like out of time puch rods are all setting in lifters somebody please help me figure this one out

 

Why did you change head gaskets? Did it run prior to pulling the heads?

Roll the engine over in the direction of normal rotation until you feel compression on the number one cylinder. Stop rotation the engine when the timing mark gets to about the 10*btdc mark. Pull the distributor cap, is the rotor pointing to the number one plug wire? If not, reset the distributor or rearrange the plug wires. If you put a spark tester on the number one plug wire, and rotate the distributor back and forth (with the ignition on) you should get a spark from the number one wire assuming everything is set correctly.

If it still pops and backfires from the carb, and you have check and verified the timing is right, I’d suspect a timing chain issue ( which is why I asked if it ran prior to tearing it apart).

Lastly, punctuation!!!

 

^^^
Commas, periods, etc. Makes everything easier to read. Everything doesn't need be done as fast as possible to eliminate confusion.

 

Everything matt69olds said is dead on; if the 307 is on its original timing set your timing could be way off. When my 307 was in my car the Smog Delete made 0 difference it didn't run any better with it on or off. My car ran like crap before and after a carb rebuild and even timing it correctly it still had no power. Once I pulled to timing cover it was clear that the car desperately needed a new timing set.

Here's what an original timing chain that is 35 years old 307 w/100K on it looks like:

 

It barely ran an it was blowing coolant out the exhaust in buckets had coolant in the oil that is why I replaced head gaskets an I know how to set timimg an how to find compression stroke I didn't take off timing chain cover if U read my previous text I have set my mark an put number 1 up repeatedly an set rotor button to number 1 still wont start could push rods be it ?

 

An the reason I mentioned that I removed smog is I didn't know if that would affect the computer even tho that was new tech then if U tear off emissions on a car now U have to send the ECU off an have everything deleted out of it but Im agreeing with probably it being timing chain an gears it has 107k on original gears an chain

 

With that many miles, you can bet the nylon gear coating has chipped off enough to jump the timing. You might even have to pull the pan to clean out the debris.

 

Thank you . So is everybody answering on my thread in agreement? That I change timing gears an I should have no problem getting this 307 running again ? An that setting it in time with the mark on the harmonic balancer an the rotor button at #1 it should do what it is supposed to ?

 

If you haven't flattened the cam or bent push rods/valves going back together, and you're convinced you have the firing order correct (which goes counter clockwise) there isn't much left to check other than the timing chain.

I've seen 100K chains/nylon original gears still be intact and I've also seen cam gears completely void of any nylon after 60K miles. It just depends. And it's not just 307s, it's basically all Olds V8s that came with nylon cam gears. Plus not even mentioning the chain stretches to seemingly about 7 feet long.

 

I dont see how anyone can assure you that. But, doing a compression test might help you get in the correct direction. If the timing chain has jumped the compression will not be very good. I know we really stretched our luck but the timing set on my Wifes 84 went almost 250K before it gave up, so I would not automatically condemn yours.

The other thing you can do is pull the drivers side valve cover and watch the #1 intake rocker while you turn the engine over by hand. That will be the very first one on the drivers side. The #1 intake should just start to move at around 10deg before TDC. The actual spec is 17 degrees before tdc but you probably wont see it start to move that early. If the intake is opening close to the correct time then the timing chain has probably not jumped.

Dont take this the wrong way but the other thing I have to mention, especially if you are a Chevy guy normally . . . . the distributor turns counterclockwise. I only mention it because I know several guys who got thrown for a loop by that simple mistake.

 

​​Agree with doing a compression test. If you get around 50 +- 10 psi the chain has jumped or is s t r e t c h e d. If it is 100 psi on most cylinders the chain should at least get it started.

Do the double check on distributor rotation and firing order as BillK suggested.

If you do replace the chain take a photo of the gear alignment in case you doubt your work later...been there😎

Good luck!!!