The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - '69 C10 327 SBC Off Idle Stumble / Misfire Help

Gromit · 11-02-2018, 01:07 AM

Noticed the crankcase breather hose is plugged in the photo - maybe that is just because you have it apart so just a reminder to have some means of venting the crankcase.. no venting could definitely cause tuning issues.

My 1970 350/350 truck has the stumble issue but not often enough to be a problem - I believe on mine it is the stock torque converter not very well matched to the torque curve of the cam. So the posters who have asked about your cam I would second their questions - your cam specs are important to have documented in solving your issue.

I can affect the stumble by adjusting my vacuum secondary rate but that adjustment seems to change with the weather..

11-02-2018, 01:07 AM	#55
Gromit Registered User Join Date: Jul 2015 Location: Central Coast, CA Posts: 498	Re: '69 C10 327 SBC Off Idle Stumble / Misfire Help - I feel like I've tried EVERYTHI Noticed the crankcase breather hose is plugged in the photo - maybe that is just because you have it apart so just a reminder to have some means of venting the crankcase.. no venting could definitely cause tuning issues. My 1970 350/350 truck has the stumble issue but not often enough to be a problem - I believe on mine it is the stock torque converter not very well matched to the torque curve of the cam. So the posters who have asked about your cam I would second their questions - your cam specs are important to have documented in solving your issue. I can affect the stumble by adjusting my vacuum secondary rate but that adjustment seems to change with the weather..