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crazy longhorn · 12-26-2002, 09:18 PM

For the most part, hot cams & fat carbs like full manifold on the vac advance.... to set them up usually requires a little recurving & an adjustable adv can. The chevs ran full manifold vac to about the mid 60's, till the carburation was leaned out going into the 70's . Most of the factory vac cans put out way too much vac timing, & were too conservative on the intial/mechanical advance for performance usage. even my old plow truck (stock 355, with a crane 266) is running full manifold on the vac advance. I would say try it both ways.......run it how it works best

12-26-2002, 09:18 PM	#5
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,402	For the most part, hot cams & fat carbs like full manifold on the vac advance.... to set them up usually requires a little recurving & an adjustable adv can. The chevs ran full manifold vac to about the mid 60's, till the carburation was leaned out going into the 70's . Most of the factory vac cans put out way too much vac timing, & were too conservative on the intial/mechanical advance for performance usage. even my old plow truck (stock 355, with a crane 266) is running full manifold on the vac advance. I would say try it both ways.......run it how it works best __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....