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Has anybody ever tried making a stock cast iron intake into an open plane intake? If so what are the results?

I've never done, nor would I recommend it either. You will end up with long and short runners and that would be even worse than what it has right now. The manifold would have no low flow manners either IMO.
Rob
 

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I have done this 5 times for the street classes that rules mandate it, and have made good power every time. I posted some of these builds here ,but it might take a while to find them ,

1 was with factory ehx manifolds and full ehx system.
 

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I have to run full exhaust also. Headers are ok..but full exhaust..the intake rule seems to vary depending on where we go...some will allow aluminum dual plane..some wont...I've got a few cast iron intakes..may just give it a shot
 

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u can open th 4 hole.......

thn it looks like an alum perf or weiand stealth....

then cut th divider down....leave @.750 ....

if poss use a 1" open spacer.......

ive done this....it extends rpm and duzz make a lil more power....

i backd it up w dyno tst and street driving.....

if u hav a questions contact me....
 

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u can open th 4 hole.......

thn it looks like an alum perf or weiand stealth....

then cut th divider down....leave @.750 ....

if poss use a 1" open spacer.......

ive done this....it extends rpm and duzz make a lil more power....

i backd it up w dyno tst and street driving.....

if u hav a questions contact me....

X2 This is what I do with the iron SCJ intakes.


S
 

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Has anybody ever tried making a stock cast iron intake into an open plane intake? If so what are the results?
I built an engine for my 1985 F250 to tow my 32-ft race trailer so I built a combo with improved low speed power in mind.

But since it is more often driven by itself (ie, not towing) and I like to drive that 4-speed truck in a spirited manner, I also wanted have some upper rpm breathability so I did this to it:



That's a standard factory iron 4-hole intake manifold to which I machined away the 4-hole carb pad's holes and made more of an aftermarket-style dual plane opening with divider. The opening is "half clover leaf" because some of the areas of the factory carb pad fall below the machined plane.

Then, the factory 1985 EGR plate (grey) is machined from a 4-hole plate to an open spacer (also half clover leaf). It is 0.850" thick, and so I now have an 0.850" thick open spacer atop an opened up dual plane intake manifold. All parts are stock, all emissions plumbing hooks up, truck passes smog with flying colors, has more power than stock, and gets better mpg than stock.

Paul
 
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