1976 305 in my chevy c10

[rick0312]

I ID'd my motor and found out that I have a 1976 305 camaro motor in my 69 c10 fleetside. Is this motor underpowered for the weight of this truck. I notice when i shift into 2nd and third gear I hear alot of valve chattering at low rpm's. At idle the engine sounds fine. What can I do to this motor in order to cut down on the valve chatter? I have tried high octane gas and i still get the chatter any advice would be helpfull......Thanks........Rick

[Troy-Built]

In the mid to late 70's the 305's 350's were notorious for soft cams. Pull the valve covers off and check and see that all of the rockers are moving the same. As far as 305's go I had one in my 68 1/2 ton that ra nlike stink but, I built it to run in a spec class truck at Indy for the super truck class. Roundy round class

[corn]

The best thing you can do for yourself & your 305 is to install a new 350 cam or mild RV cam, lifters & new chain & gears in it. The stock cams are not good. I had an '81 that I did this too & it made a whole different truck out of it...

[rick0312]

when i pull the valve covers off... am i looking to see if some of the rockers are sticking? what should I specifically look for. sorry, but i am a novice when it comes to engine troubleshooting........thanks......Rick

[Ron 586]

Check your timing. Some guys try to pick the engine up by advancing the timing. Also check to See if they have the vacuum advance hooked to ported or full time vacuum ports. Disconnect vacuum line at distributor and plug line. Make sure the engine is at low idle so you get accurate reading and set timing to specs. then after locating ported vacuum on carb. hook up vacuum line to distributor. Road test and see if the noise is gone. If it is a little doggy bump timing up in 2 degree steps until you get performance back or rattle. The only thing you need is a timing light and a 9/16 wrench to loosen the distributor. Good luck.

[corn]

If you have a lobe gone the rocker wont move up and down very far. Just try to watch all of them as you crank it over or as it sits & idles. There may even be a loose one...

[Ron 586]

If you are not sure of what I was talking about you will need help.

[rick0312]

thanks for the info. I think i might install an adjustable vac advance and try to dial the ping out. no pingig at idle, but lots at part throttle. thanks again i'll see if that does it.............rick

[skchevota]

you should not need an ajustable vac, advance, if it is pinging at part throttle then your timeing is set to high or your mechanical advance is stuck. check the mechanical and vacume advance for proper operation, if all is ok then retard your timing 2degrees at a time untill the pinging stops.