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PanelDeland · 02-16-2011, 04:53 PM

I'm going to suggest you bite the bullet and go to an HEI also.Much better and more consistent spark.

Beyond that,you may need to do a compression test and make sure you have a decent motor to try tuning.Usually a 250 will run till it's wore slap out but after 40 years.......
Sounds to me like a vacuum problem but you seem to have hit all the areas that I would suggest.However you can disconnect the vac line and suck on it to see if you're actually getting movement from it.The fact that you can richen it and have it run makes me wonder if you don't have an internal leak in the carb.
Does it have PB? If so there is a possibility that you have a vac leak in the booster.
Try blocking off the vac line to the booster and adjusting the idle.Or pull a vacuum on the booster and see if it holds.

Those are the things I wound up checking on mine.The vac advance wasn't working.I changed the vac in the dist and it got much better,but it really woke up when I put the HEI in.

02-16-2011, 04:53 PM	#5
PanelDeland I am a Referee of life. Join Date: Jun 2000 Location: Greensboro N.C. Posts: 13,992	Re: inline 250 driveability I'm going to suggest you bite the bullet and go to an HEI also.Much better and more consistent spark. Beyond that,you may need to do a compression test and make sure you have a decent motor to try tuning.Usually a 250 will run till it's wore slap out but after 40 years....... Sounds to me like a vacuum problem but you seem to have hit all the areas that I would suggest.However you can disconnect the vac line and suck on it to see if you're actually getting movement from it.The fact that you can richen it and have it run makes me wonder if you don't have an internal leak in the carb. Does it have PB? If so there is a possibility that you have a vac leak in the booster. Try blocking off the vac line to the booster and adjusting the idle.Or pull a vacuum on the booster and see if it holds. Those are the things I wound up checking on mine.The vac advance wasn't working.I changed the vac in the dist and it got much better,but it really woke up when I put the HEI in. __________________ The 47-present Chevrolet and GMC Truck Message Board Network,it's owners,moderators,members,and associates of any type should not be held responsible for my opinion. You can't fix stupid,not even with duct tape. "My appearance is due to the fact that "GOD" does punish you for having too much fun!" Barrett-Jackson has perfected alchemy,they make rust into gold! "You can lead a horse to water but you can't saddle a duck" "Cleverly disguised as a 'Responsible Adult' "Sometimes your Knight in shining armor is just a retard in tinfoil"