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98 Cobra or 03 Cobra conversion?

  • Thread starter Thread starter 5.0 LX Sleeper
  • Start date Start date Jul 2, 2009

5.0 LX Sleeper

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Everett, PA
Jul 2, 2009
#1
  • Jul 2, 2009
  • #1
Hey all, right now I have a 90 LX with a 331 and and s-trim on it that runs pretty good but it really has the street manners of a drag car and I'm getting tired of it and want something new. I was wondering what the pros and cons of each way would be? Right now I can get a full 98 cobra with 97k on the clock for $5,500 or just the drivetrain for an 03-04 cobra from MPS for $9,500. If I were to swap either combo into my LX which would be the better way to go? I don't want to make much over 400rwhp out of either combo. Thanks for your help!!
 

squeak93

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Jun 2, 2005
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Jul 2, 2009
#2
  • Jul 2, 2009
  • #2
03/04 hands down is the best of the two.

The 98 is a good car to and will provide ALL the parts you need... ie wiring and computer.
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
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Jul 2, 2009
#3
  • Jul 2, 2009
  • #3
you'll need more parts with the 03/04 swap.

I'd go with the 98 Cobra, part out what you don't use and then use the difference for a supercharger.
 

5.0 LX Sleeper

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#4
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how much can the stock bottom end on the 98s handle? I know thats a big upside of going with the 03/04 is that they can take a pounding.
 

squeak93

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#5
  • Jul 2, 2009
  • #5
The 98 will have a STOCK aluminum TEK SID block (the most sought after stock block). The rotating assemblys are good to 400 rwhp in gt's, I'm not sure how much stronger the cobra is. I know the crank is a lot stronger but think the cobras still had the chitty rods (weak point in the gt's).
 

1low03gt

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#6
  • Jul 2, 2009
  • #6
'03/'04 swap for sure!!!
 

GroverDill

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#7
  • Jul 2, 2009
  • #7
Put a bigger pulley on the S trim and retune the 331 for less boost and better street manners.
 

BlownStangGT

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#8
  • Jul 2, 2009
  • #8
If you can buy the entire 98 cobra for 5,500 and its in decent shape I would do that. Slap a blower on it with the proper fuel stuff and some exhaust and then you will have a track car (fox) and a stret car (cobra). Most of the 96-98 cobras with blowers on them make 450at the wheels with no problems
 

wicked93gs

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#9
  • Jul 2, 2009
  • #9
another thing to think of...the 98 engine will weigh quite a bit less...aluminum vs. iron block, as mentioned the teskid is the best, just 8psi should get you close to 400, or go the other way and do it NA, either way its easy to make power on a 4v
 

5.0 LX Sleeper

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Jul 3, 2009
#10
  • Jul 3, 2009
  • #10
Thanks for the replies everyone. If I go with the 98 setup, how much can the T45 take and how easily would it be to get say 350rwhp NA or would it be best to just put a single turbo or supercharger on it and call it a day?
 

EPIK

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#11
  • Jul 3, 2009
  • #11
GroverDill said:
Put a bigger pulley on the S trim and retune the 331 for less boost and better street manners.
Click to expand...

Exactly... I would take that 331/S trim combo over the 03/04 swap any day of the week...
 

LaserSVT

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#12
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I think everyone hit it pretty close to what I was gonna say.
The 03/04 is bad ass as all hell but if you only want 400-450 rwhp the better bet would be the 98. The cast iron 03 will be over 650lbs on the nose of a car with bad balence already. The Teksid will be 200lbs lighter and is a better block. If you buy the 98 and pull its engine/computer/harness then you will have all you need to do the swap. You can part out the Cobra for more then enough to cover the cost of an ATI with intercooler and pump down 425rwhp with no problem. I would suggest getting an AJE or MM K-member as well to help keep the car balenced. Also, dont disable the IMRCs on the modular cause they help alot and by switching the new comp over you will still be able to controll them.

Now here is the fun part. The Teksid block and 96-98 Cobra crank can handle more power then you will ever want to throw at it. So down the road if you decide 450ish (the limit for the rods/pistons) is not enough then all you have to do is get some forged dished pistons and some forged rods, turn the boost up from 8psi to 16 and put down well north of 600 rwhp.

On a Fox with a good suspension you could pull high 9s with the A/C on


EDIT: BTW, the 4.6 N/A with long tubes and all the bolt ons will only be good for 315-325 rwhp at best. They do love boost though! The KB is my number one choice as it makes the little engine pull like a big block giving you over 500 rwtq at just 2100 rpm Down side is they are $1000 more then the intercooled Vortech/ATI kits and they dont have an intercooler avaliable for the "B" heads You can use a meth kit but I hate having to constantly fill another tank. Without an intercooler the twin screw will never make the power that a centri can without hurting the engine.

The trans will hold 450+ as long as you are not doing constant 4K+ drag strip launches.
 

wicked93gs

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#13
  • Jul 3, 2009
  • #13
I personally vote for a turbo system, which if you piece it together yourself wont cost any more than a supercharger without the parasitic drag on the engine...not to mention its a lot easier to intercool it than a roots-type S/C, I plan on doing a simple 8psi twin turbo setup myself, pretty basic that should cost less than $2000...but then, I'm pretty experienced at the turbo game by this point and can make my own piping and manifolds, which takes a good chunk of the cost out of it
 

5.0 LX Sleeper

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Jul 4, 2009
#14
  • Jul 4, 2009
  • #14
Thanks for the replies everyone, I think I'm gonna go with the 98 setup.
 
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