is there advantage to cutting the dividers out like the doc mod on 4 barrel nailheads. i know ta makes one but i have a good stock intake and dont really want to spend another 400 bucks for a ta aluminum unit. i had planned to port match it anyway. just wondering if its a good idea on the small block as well. thanks.
nailhead , 350 , 455 etc - I would have to guess it would be worthwhile . I almost did it when I gave my intake a quick port match . I would with further mod's but I grabbed an SP3 intake . not sure if anyone has done a before-after manifold test comparison .
i know nailheads its worthwhile just making sure i wasnt hurting myself on the 350. this is my budget cruiser so its not like i want to put a fortune into but i do want to make it a little better especially for free basically. i already had the 4 barrel intake i bought it when i had that 83 along with headers and a cam so im not out no money just a little time. i would like to at least get the heads ported out later as well. im shooting for a 300 hp car idk if im on the right track.
Maybe a carb spacer would have a similar effect? You're basically increasing the plenum volume with the Doc mod.
well im running a square bore adapter (edelbrock carb but going to a sniper around xmas) that adds a half inch. so would it help to do both? its not very much work like i said its not on the car yet. laying in my storage building at dads and im going to port it as well since its not on it.
Am I wrong? The "Doc mod" doesn't connect the secondaries of the upper and lower planes. It just opens the gasket surface from upper front to upper rear, lower front to lower rear. This would be useless with a 3-barrel, 'cause there's no clearance for the big secondary throttle blade. You'd have to remove metal BETWEEN the secondary bores of the intake. I've never understood how the "Doc Mod" accomplished anything. The increase in plenum volume is slight "Gasket matching" the manifold is a total waste of effort. The flow problems aren't at the gasket surface, they're at the pushrod pinch and the bowl/valve seat.
im doing the heads as well so i figure why not. im running a 4 barrel however so i know very little about 3 barrels but the mod should give a dual plane set up or round about if im correct. ive seen the same mod on olds engines.
I would get the SP3 and be done with it or get the TA DP intake then you won't need no stupid adapter with either intake plus you take that heavy weight off the front. Who wants to hold that heavy intake to drop in when there are lighter and better ones available.
its 400 bucks this is free i wont need an adapter after i get the sniper on it if i get the quadrajet model and 50 lbs of weight aint going to help a 72 lesabre in the weight department enough to matter.
i thought about that but im trying to keep it sorta original plus i have all this stuff laying around already. so im not out any money just my time. as in my other post im not really concerned with trap speeds and times just want it a little better than it is to drive around. on top of that im going for a highway car build so i really dont want 455 mpg. right now it gets excellent mpg to be as big of car as it is.
