First I would like to compliment you guys on a great well managed site. I have been a user since last spring and am constantly learning new things.

I am planning on building a 460 (466) this spring to put in my 78 Ranger SC (see gallery). So far I have aquired a complete set of D20E heads with new guides, seals, and Comp 924-16 springs. I have located a donor motor out of a 77 Lincoln for my block, crank. rods, accessories, etc. My plan is to rebuild this setup with Speed pro H535 pistons, a Comp X4270 cam (270/278 adv 226/234 @.050 .554/.574 lift 111/107 dgrs), roller rockers, a Weiand stealth with a 770cfm Holley Truck avenger, L&L headers with 3 in exhaust/flowmasters, and MSD ignition with a recurved stock dist. I plan on having the block decked to get me as close to 9.8-1 compression as possible and the entire rotating assembly balanced. I have a good machine shop here with a guy that loves 385s(and has been loving them for 20 years). My planned usage is a combination of off roading and I occasionally throw a 1500lb camper on my rig and tow a trailer with ATVs and camp gear (about 3000 lb) up and down Western Montana passes. The rig is not a daily driver so I am not worried about gas mileage. The truck weighs about 5800lbs empty and I will be bollting the 460 up to a ZF 5 speed/NP205 and 4.10 gears with 35 inch tires.
I have destop dynoed this engine combo out to about 445 hp @ 5000 and 524 ftlb @ 3500. I like this combo because it holds over 500 ftlbs all the way down to 2000 rpm, at least on the computer anyway.

I have two questions though. The Stealth manifold comes in two varieties, one for regular and one for the CJ/SCJ with the bigger ports. Which one would best suit my needs? If I went with the CJ/SCJ would it slow down my intake velocites at lower rpms too much and make it doggy? I still want this thing to pull all the way to 5200 without loosing its breath. Would the regular Stealth hurt me at all in that respect? My second question has to do with the D20E heads. They are stock right now. Should I leave them alone or go for a mild port job on the exhaust? The only flow numbers I could get to use on the destop program were with ported exhaust flows but I don't know how this would work in the real world.
Deen, George? Anyone else with experience? Do you have any advice or opinions?

Thanks,
DeanG

 

The D2oE heads are slightly larger then a passenger car head, but smaller then a CJ port. I'd get a passenger head style Stealth and see what needs to be done to port match it to the PI head. Even if you don't port match it, it will be smaller then the head which is better then being larger.

 

I think with your combo the standard Stealth would be your best pic. Its a very good intake, and you'll want to stick with the higher runner velocity with your weight. You'll want to at least get your exhaust side of those heads ported as thats where they will need it the most...I never skimp on my head work because that can really strangle an otherwise potent build.

 

I think the regular Stealth would be the way to go. I think the PI head ports are only slightly bigger than the regular ports. The regular Stealth should give you enough meat to port it out to fit.

JJ

 

I'd go with the SCJ Stealth. The larger ports transitioning into the slightly smaller ports of PI heads will create a venturi effect, increasing port velocity.

 

There was a quote from an old school Ford Performance book regarding the use of the SCJ intake manifolds on regular heads. It said something like, despite the obvious port mismatch simply bolting on the better flowing SCJ intake was worth 15 hp, or something to that effect. I am not sure that applies when comparing a SCJ Stealth manifold to a regular Stealth manifold, as a regular Stealth would likely net that 15 hp if not more over the stock manifold anyway. I'm not sure I would want that large port mismatch unless I had documented proof of a hp/torque gain.

JJ

 

your right BIGSNAG ,, i have read the same thing and was told this from an old man who dealt in lincoln motor's. he told about the OFFENHAUSER 360 degree intake manifold C.J. and how he said that he used them on stock heads for some outstanding power increases. C.J.