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Discussion Starter #1 (Edited)
So according to my research the 98 cobra makes 305hp 300tq and my 98 m8 lsc make 290hp and 290tq
I know the cobra has more aggressive intake cams and a better intake but are the heads the same?I know the cobra crank is forged too.
I supposedly already have upgraded intake cams I also have exhaust,90mm mafs,42lb injectors,and a tune..
What gains can I expect from just a cobra intake swap? Will it add a better growl to the engine or increase my intake noise? Can someone forward me a install thread onto a mark8 I haven't found one with pics or a decent detailed write up. I'm wondering what all exactly needs to be swapped over or changed..does the egr line up? Reason I ask that is because for the final tune I will just have the egr turned off for when I do do the swap .
Would it be worth all the work to do cobra heads? Would the whole cobra hci really only be worth 15 tq and hp? Or with my other mods can I expect a little more?
The intake is a for sure and heads a maaaaaaybe. I been seeing complete heads going for dirt cheap..i could have a whole cobra top end and all stuff to install it for under 1000$ . Or I could get just the intake for 300$ range.
What about the later style mach1/cobra intakes, do they fit onto my heads or am I limited to just 96-98 . I read I can use a marauder one but I'm not gonna move my battery and stuff like that to make that one work..
 

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The Parts Guy
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The '96-'98 Cobra head castings are the same as those on the '96-'98 Mark VIII.

The Cobra intake is a worthwhile upgrade to a Mark VIII.

"C" head intakes will not fit on "B" heads.
 

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Discussion Starter #3
I have B heads correct?
I wasn't sure if they were the same as cobras , so much misinformation I've gotten..
Makes sense because of the power difference though.
Depending on what all involved i want to do a cobra intake now too..
How come the cobra got a forged crank and not the mark? Is it for higher rpms from the manual?
 

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The Parts Guy
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I have B heads correct?
I wasn't sure if they were the same as cobras , so much misinformation I've gotten..
Makes sense because of the power difference though.
Depending on what all involved i want to do a cobra intake now too..
How come the cobra got a forged crank and not the mark? Is it for higher rpms from the manual?
Assuming you have a '93-'98 4.6L 4V, you have "B" heads. The '96-'98 Cobra didn't "need" a forged crank. I can't say with any certainty why it received one.

This might be more misinformation but I think only manual Cobra's got the firged crank. Not the autos.
Well, that's right, because all '96-'98 Cobras were manual. What you're thinking of the is '03-'04 Mach 1.
 

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I had my 96 Cougar put on the dyno and yielded 266RWHP. I have degreed 96-98 Cobra cams, Cobra intake manifold, 24lb injectors, 80mm MAF, dual exhaust and a Lonnie Doll tune from Blue Oval Chips. I would recommend degreeing the cams because they can be as much as 9 degrees out of sync from left to right bank, and in the end can gain HP.
 

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Assuming you have a '93-'98 4.6L 4V, you have "B" heads. The '96-'98 Cobra didn't "need" a forged crank. I can't say with any certainty why it received one.



Well, that's right, because all '96-'98 Cobras were manual. What you're thinking of the is '03-'04 Mach 1.
Thanks for catching me, yes, the Mach 1's.
 

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I was going to swap my B heads to C when I did my rebuild but decided not to because I wanted to get it back on the road fast.. lol.. a year and I still have the engine and trans out, but they are rebuilt and ready.. :grin2:

I have 99 navigator heads and an 04 Aviator intake I was matching up and welding a larger TB plate on when I decided to just go back to what I pulled out. The guys a Sulivan Performance said that the B heads are better street than the C but the C heads tumbled air and produced more mid-range torque. They convinced me to use the 5.4 navigator heads, which bolt to the block but the 4.6 intake won't fit without some modification since the ports are larger on the navigator so the intake needs to be welded a bit and opened up to keep from an air leak and getting a good port match.
Sullivan told me all engines that came from the romeo plant had forged internals as well, and that all 4v engines were built there but cranks were special for the Lincolns. Not sure what that means exactly though. I know my 4V came with a 6 bolt crank ( doesn't look forged but Who Knows it looks real nice if cast but has a thin parting line), also an aluminum block and cracked rods with floater pins and hypereutectic ( I think, very smooth and light ) pistons. Mine is a 95 not sure what the different years did.
 

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If your crank has 6 bolt holes, it will be missing the middle two balance weights, indicating a cast crank.

If B head inlet ports weren't big enough, there's the Navi heads, lol.

Are you running a blower or a cam?
 

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The Parts Guy
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I was going to swap my B heads to C when I did my rebuild but decided not to because I wanted to get it back on the road fast.. lol.. a year and I still have the engine and trans out, but they are rebuilt and ready.. :grin2:

I have 99 navigator heads and an 04 Aviator intake I was matching up and welding a larger TB plate on when I decided to just go back to what I pulled out. The guys a Sulivan Performance said that the B heads are better street than the C but the C heads tumbled air and produced more mid-range torque. They convinced me to use the 5.4 navigator heads, which bolt to the block but the 4.6 intake won't fit without some modification since the ports are larger on the navigator so the intake needs to be welded a bit and opened up to keep from an air leak and getting a good port match.
Sullivan told me all engines that came from the romeo plant had forged internals as well, and that all 4v engines were built there but cranks were special for the Lincolns. Not sure what that means exactly though. I know my 4V came with a 6 bolt crank ( doesn't look forged but Who Knows it looks real nice if cast but has a thin parting line), also an aluminum block and cracked rods with floater pins and hypereutectic ( I think, very smooth and light ) pistons. Mine is a 95 not sure what the different years did.
Mark VIII's, Aviators, Marauders, Continentals, and automatic-equipped Mach I's received cast cranks. The rest of the 4.6L 4V's ('96-'04 Cobra, '03-'04 manual-trans Mach I's) received forged cranks. The only 4.6L 4V's that received forged rods and pistons were the '03-'04 Cobras. "B" heads are not at all superior to "C" heads on the street. Ditch your rods and pistons if you're going for any sort of a performance build (400+ rwhp). They are the weak link.
 
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