While out under the hood today, I was thinking about the mystery motor in another thread and thought it would be good to know that the engine I'm working on that I believe to be a 350 is actually a 350. So I cleaned off the pad that has the codes and it turns out that I don't have a 79 350, I have an 81 350 since the suffix is UHW. So idk if when the engine was rebuilt in 95, if the original block was a 4 bolt main that they stole and replaced with a 2 bolt, or if the old block was bad, or what but at least it's a 350. With the way it's been acting I was begining to wonder.

 

Okay, so I hooked everything up like you said, got #1 tdc, rotor pointed where it needed to be, hooked everything up, it started right up had my mom come put the accelerator down to get it to 3000rpm and set it to 6* btdc without the vacuume advance. It ran great, sounded great, nothing smoked. I was satisfied so I shut it off, unhooked the timming light went in the house for maybe 5 minutes came back out hooked up the vacuume line, started it, it ran a little rough figured it was just the vacuume coming in, ran it for a bit seemed to level out, pulled it out of the garage got about 5 seconds down the driveway before it started running rough it died, barely got it started and now I have a loud nock. I pulled back into the garage shut it off hooked on the timming light checked it it was about 2* atdc got it back to 6* btdc but it still has the loud nock. I have not a clue what is wrong or what I've done other then hooked the vacuume back on the distributor. so I'm pretty much burned out on this thing being a piece of crap because of me working on it, I guess I'm waiting till my dad can help me, he told me to get a oil pressure gauge with copperline and put that in and just wait on the rest which is fine with me at this point.

 

That would have sucked if it wasnt a 350, it is a PO when you trust someone and check the #'s after the fact and it's only a 305. It happend to me, man I was P'd.

 

This is just a shot in the dark. But from reading everything else in your thread, it sounds to me like maybe your timing gear may have jumped a couple of links. I hope it's simpler than that, but I had a similar occurence with a pick up I was fixing up a couple of years ago. Thought I had it timed right on the money, shut it down, and came out to fire it up and found myself in the same situation you're in. Loud knock and all.
I hope not. I hope it's a simple fix. Good luck

 

Well I'm gald it ran for a second. I'm trying to remember if the vac line should be hooked up when you set the timing. Try setting it with the vac. advance hooked up. I am pretty rusty and my dizzy doesn't have vac. advance on it.

Lets see your dizzy should have 28* mechanical advance in it. Plus the 6* initial that you set in it, that's 34*. Right where I wanted you to set it. But then I had you hook up the vac. But I don't know if the vac adv. is on top of the 28 already in the dizzy or adds to it. Crap. Honestly I don't know. You might want to look that up.

 

We'll I thought I might just redo everything I did today again. Then when it comes to the timming have the vac hooked up. But even after that if it still has the loud nock I'm still hosed. But before that happens I'm gonna install a oil pressure gauge because my dad thought the oil pump might not be working, so an oil gauge, then probably redo today's work then if it still has the nock with good oil pressure idk what I'll do. My dad told me to take the belts off and run it to see if the nock is in the engine, cause at first he thought it was my power steering because I left the big a/c-ps bracket off since it wasn't reallly doing anything other then get in the way, but I was like really that's not where the noise is coming from I can tell its under the valve covers, you can tell from the sound and if he wasn't half deaf he could too, he's just getting to old to be tinkering, but to make him happy and so I don't have to listen to his crap about that bracket I put it back on. Obviously that didn't solve the problem of course, but sooner or later I will have this crap figured out I just hope that doesn't intail a full rebuild to get to that point.

 

man I hope not too, how would I even check for that?

 

And damon sorry man, but I have no clue about anything you said in the second part of your post with the 34* and stuff. lol I'm such a noob I have no clue what to try to look up for that.

 

Why did you run the engine at 3000 rpm's to set timing? That's just weird. Timing should be set with the vacuum advance disconnected and the end of the line plugged that goes to the carb, so it doesn't have a vacuum leak. This should also be done at idle, not 3,000 rpm's!
A bad timing gear will generally show up as a timing mark that wanders a lot at idle when you put the light on it. If it wont hold steady at a even idle it's gone. Ar eyou sure you've got a stock cam? If the cam isn't stock, then timing marks mean nothing at all. You can set it to factory specs, but if it's not a factory original cam the timing will be way off.

 

Maybe he was talking about getting all his timing in before 3000 rpms?