I just received my new Weiand Stealth. I am in awe. The ports on my 680 horsepower Chevy aren't half this big. My current combo is a rock stock 1987 460 in an E-350 with 4.10 gears, c-6 low stall converter and shift kit. I am basically just resealing it and removing the emission controls. No smog checks in Oregon. I also am putting in a straight up timing set.

What I want is the most torque possible from idle to 4500 for now. My total combined weight is about 16,000 pounds. I'm switching from diesel to gas so I have no idea what to expect. I bought the Stealth after reading as much as I could on this board but after seeing it and knowing what I know about port volume verses flow I have to believe these huge ports will be a little lazy compared to a smaller intake like a straight Performer. I hate to think that when it's cold out and with the tight converter when I'm hooked to the trailer and hit the gas from an idle it may loose all signal to the carb and end up just popping through the intake and dieing. Am I wrong or can a stock 460 handle this manifold?

Though the Stealth looks way cool it will rarely be seen in my van. More important will be keeping up with the 8.1 liter Chevy's on the hills.

What are you guys using?

 

I believe that there are two models of stealth manifold one for the stock ports and one for the CJ intake ports perhaps you have a CJ version. The stock 460 ports are not super big, but the CJ ports are huge. Eric

 

It's not the Cobra Jet. It's part number 8012 which is for the plain 460. The ports match the heads fine but the internal dimensions just seem very large. Maybe I'm just not used to looking at big block stuff. I'm worried about carb signal and off idle performance. I'm sure on the open road it will wail.

 

The specs on the intake say Idle to 6800 rpm. Being it is a dual plane manifold, it should have enough low end grunt to pull the weight. It is taller than the Performer and this will extend the top-end range. The big ports have big cylinders to fill!! I think that it should work fine.
Jimmy

 

Stealth is way to big! Don't believe Weiand's ad. No mainfold can be good from 0-6800 rpm. Tried one & took it off. Performer RPM also too large. For low end torque, use the Performer.

For really improved torque, check out www.headerdesign.com. and read about header designs. Great site!

You will find out that a 750 cfm carb. is too big for what you want to do. I am running a 625 cfm Carter. Tried an Edelbrock 750 ans lost a substantial amount of my midrange throttle response. Your 268 cam is probably too big as well.

For improved performance you will need to cut a small slot, approximately 25% of your carb. venturi in the divider plate between the two plenums. The Performer RPM comes with slot cut out, but it is too large and hurts low end.

I have learned a lot & paid for every bit of it. Good Luck

 

uh, if this is in a later model econoline, have you checked for doghouse clearance on the top? I have a 351w with a performer RPM, 1-inch open spacer(351w RPM's have mixture problems), and an edelbrock 750 on top....4-inch open filter, drop base, and I have about enough room to barely squeeze my flat hand in there to tighten the wing nut on top.....

 

Up to 3500rpm, stock or Performer manifolds are superior to the Performer RPM or Stealth. With an otherwise stock engine, I doubt you'll be seeing much more than 4500rpm as the cam is also ground for low emissions. Changing the timing set to straight up will help performance.

 

FYI, I called Weiand & asked if they had dyno shgeets to prove the Stealth was good from 0-6800 rpm. Their answer was "NO"!!!

Warning, warning, warning, DO NOT USE THE FELPRO #1230 competition intake gasket!!!!! I absolutely guarantee it will fail!! The last gasket I installed was a 'ROL' & it seems to be working. I also understand Ford has 2 new intake gaskets for the 460. One is .060" & the other is .120"

Also, buy the more expensive Cloyes timing gear & chain (approx $87). According to Cloyes it has a much better timing chain, less stretch & lasts longer. The gears are the same.

Use 'water only' in your cooling system during the cam break in. Anti-freeze will eat the rings & bearings if you have a leak as I did!

Change your oil immediately after the cam break in. The cam lube will plug your oil filter. My oil pressure went from 70 psi, to 56 psi, to 46 psi in 3 days. Scared me to death.

 

The van has a 3" body lift so I hope it will clear. I also called Holley yesterday as they provide the tech service for Weiand and that guy said it would be fine but would work best with a 750 carb and headers. I can do the carb right now but the headers will have to wait. On the highway I am guessing my rpm are about 2800 to 2950 at 65. The carb he recomended is a Holley 4160 series, pn#080508S 750 cfm vacume secondary unit.

The cam is the stocker at this time so break in is not an issue. My goal is to eventually get to 500 foot pounds of torque with the 460. It seems that a lot of you are using the bigger intakes when you get up to that power level. Will a plain Performer make this number?

I did plan on using the Fel Pro gasket. Why do you believe it failed? Did it have a big vacume leak or did just the water ports leak? Being I have built a lot of small block Chevy's I have got into the habit of never using the end rail gaskets. I just run a heavy bead of silicone on the ends and set the manifold into it. That way the end rails can't hold the manifold up in any way and I never have oil leaks.

I really appreaciate all of your input and I thiunk this is an issue many are interested in. I have read every mention of the word Stealth on this board for the last year and It is still hard to form much of an opinion on which manifold is best for my daily driver and hard hill puller. I'm not afraid to lean on it.

Thanks

 

The FelPro #1230 is a paper gasket with the blue silicone around the ports. It does not have a cutout for the exhaust crossover. I have installed them without cutting out the exhaust crossover & having cut it out. In both cases the heat causes the gasket material to deteriorate & then you start sucking oil up into #2, #3 & #6, #7 intakes. When I called Felpro, they agreed you would experience 100% failure. I have had approx. 8 installations fail!!!! I have had the gasket distort, slip and split. And, no I did not over torque it. I use silicone (ultra Gray) in the valleys. They do not recommend it for street use. The standard gasket which comes in their engine gasket kit may be O.K., but I have never tried it.

I have made (& paid for) many mistakes in having my 460 rebuilt three times. I have an Edelbrock 750, a Weiand Stealth, a Reed cam and a timing gear & chain sitting on my bench to prove it. I would be glad to share my experiences. Please feel free to call me any time at 425-226-6033. This is the Seattle area.

 

Is this the "PrintoSeal" line of gaskets?

 

OK. Here we go. I have a dead stock 79 460 with a weiand stealth intake, out of the box edelbrock 750 carb, and headers in my F250. I would definately recommend this intake and carb combo. It was the single best mod that I have made to the engine so far. Better throttle response and more torque/horsepower from idle to redline. I tried my friends 600 edelbrock also but prefered the 750 because it ran a little better. I also used the felpro #1230 gasket with, guess what, NO PROBLEMS whatsoever! I agree with holley that the intake works best with a vacuum secondary 750 carb and headers and I dont think you will be dissapointed with the results.

 

What does everyone think of using the one piece valley pan model gasket with an aluminum intake? Will it work?

 

The paperwork says in bold print not to use the valley pan model. So, the recommended print-o seal is not reliable and the factory says no to stock. Can we agree that clearly something is superior and recommend it?

 

I'm in the process of a rebuild on a 86 460 from a Ext Cab 4x4. I'm debating between the stealth and the performer, and haven't made up my mind yet. I will most likely use a crane cam with .487/.518 lift, headers and a Holley 750 vac. I will be towing a lot, and a little playing. I'm still not sure what I want to go with. I've been looking for something definitive between the two, but haven't seen anything that makes me want one over the other. But, Big F250 pretty much has the same truck as me, except I have 3.55 gears, and he sound very pleased with his set-up.
Chuck