347 stroker vacuum

jcleavdog · 10-10-2009, 06:57 PM

i'm putting a 347 stroker engine in my 78 ranchero in the spring. it has edlbrock aluminum heads 205 valves and a 485-523 lift cam with 1.6 roller rockers and a super victor junor intake.650 holley carb from a ford mustang. the quesion is there enough vacuum to run the msd distibuter and carb. with using roller rockers.

93ranger_danger · 10-11-2009, 01:28 AM

the roller rockers shouldnt effect the vaccum beyond the limits to run the distributer and carb
if your going to do that much work might as well buy a blower then you wouldnt have any problems at all besides speeding tickets

jcleavdog · 10-11-2009, 11:31 AM

I want it to look old school. It already has about 450hp. maybe a blower in the future. It is a stock looking sleeper all except the rubble. thanks for the anwser.

theoldwizard · 10-11-2009, 02:13 PM

Long duration cams can affect vacuum, especially at idle.

QuoteWarz · 10-21-2009, 02:58 PM

Yes, the cam can definitely affect the vacuum so you might want to consider getting a more streetable cam if it bothers you. The roller rockers shouldn't affect anything at all.

danomt · 11-04-2009, 05:15 PM

The problem will not be running the distributor as vaccum is not required. the carb can be modified. Without the duration, vaccum will be hard to perdict, the the problems will be with vaccum assist brakes, vaccum accsesorys, etc. Roller lifters change nothing, but the 1.6 ratio will affect lift, but not much on the duration. Being as you allready bought the cam, have it installed, try it. What the heck... DanO