Hey I have a 79 K-10 with a 350 in it. The problem is, it will only start when cold. It runs like crap, sputters, coughs, and back fires out of the carb. Then when its warm it will not run at all. I have changed the plugs, wires, and added an Accel superstock H.E.I. coil. Whats the deal? Timing chain? Module? Cam lobe gone? Im clueless here and I need ideas before I throw more money at it, thanks for input.  

Does it have points? If so file and set them, check your timing, being that old it is possible that the advance weights in the distributor may be causing some undesired effects, Check to see if it is getting adequate fuel, Check your fuel filter, another thing that 350's are bad for is Vapor locking. I always replace the steel line that runs from the pump to the carb with a rubber line, it does seem to help with vapor lock. Another thing I would check for is a valve sticking. Check all these things and give us a holler back and we'll give you more possible things it could be. but those are the fast and cheap cures.  

Oh yeah I almost forgot. Make sure the wires are in the right spot on the distributor. Find TDC and pull the cap to see where the number one wire goes. remember the firing order is 1-8-4-3-6-5-7-2.  

Yeah, I'm way ahead of you there, has a braided line from fuel pump to carb, had vavle covers off to see if all rockers were moving, they were. And firing order is correct, however I think it may have jumped time by 1 tooth. Possible? I'll ckeck that tommarow, by the way it has an H.E.I. dist., and it ran right before my last battery went bad and was replaced along with the starter. Could the coil be getting too little voltage? how would I fix that? The spark is orange instead of blue-white like normal, with a new coil this is the only other thing I can think of. Perhaps I left the hot wire loose on the starter and the coil is not getting enough voltage. Thanks for the help.  

You might try changing the module in the distributor. I had one go bad before and they aren't hard to change. another thing you might check for is a cracked or broken vacuum line. keep us posted

 

Is it old? did you check the pistons for wear that will cause blow by. check the oil ring, one of the windows could be plugged, that why it don't run at high temps. Or i guess you could use it for a winter truck.lol lol ......does the oil guage read at all. not sayin that it is out of oil, but the oil sender might have the magnet stuck to it. the one that picks out shavins....just a thought ........had it happen almost blew the engine.

Hey guy's thanks for all the info and advice, turns out the jerkwad that had it before me used silicone on the entire intake, so it had a horrendous vacum leak. Go figure.  

Glad to hear you got it fixed. Sorry we didn't help that much. Keep it safe and keep it wheelin