1994 GT HCI advice please

Discussion in '94-95 5.0 - Specific' started by MTB'94, Apr 20, 2015.

  1. MTB'94

    MTB'94 New Member

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    Hey guys and gals,
    Great site! New member but long time Mustang fan. I've owned three now over the years and I recently bought a real nice '94 GT. The car is fun and has normal bolt ons. Long story short(er) I want to put some GT40 heads on it. It already has a Cobra intake and I just want to match up some decent, and cheap, heads and can to pump it up a bit. With that said, I'm mechanically inclined but have never done any major engine work nor do I have any special tools. Would I just be better off paying someone to do it for me? The car is not daily driver so time frame isn't an issue if it took me a weekend or two to finish. I'd like to do it myself bc I'm OCD so would feel better if I do it. However, my patience level is not what I'd like it to be.

    ive researched the subject quite a bit but can someone direct me to a write up or could tell me the hardware needed for something like this?

    Thanks in adavance!!!:headbang:
     
  2. SLOW95GTS

    SLOW95GTS Active Member

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    It's not too hard if you can take your time on it. It can be done with simple hand tools, a pulley puller, and a torque wrench. Remember to get a Chilton/hanes book for torque specs, and tightening patterns. Get a magnet tray for all the bolts so you take out. Lastly remember or label vacuum hoses to where they go. If your putting a cam in I'd recommend getting a tune.
     
  3. tykempster

    tykempster Member

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    I had no prior engine experience at all and have a successful HCI intake swap, did gt40p heads and intake, and a b cam. I just took my time and asked lots of questions on this forum and others :) Big performance increase! I also did a 70mm throttle body, tune, and headers, along with a new distributor, better coil and wires. I would believe every bit of 75+hp at the wheels from all that, when I supercharge the car it will get dynoed however.
     
  4. tykempster

    tykempster Member

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    If you're looking for a gt40 swap writeup, just google the topic you'll find lots of stuff.
     
  5. MTB'94

    MTB'94 New Member

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    Thanks for the replies! I'm leaning toward doing the swap more but another big question I have is what hardware will need replacing along the way? I know I'll need all new gaskets but maybe the head bolts too? I want to have some good gaskets etc. bc I want to put a 100 shot on it sometime later. I will be taking it for a dyno tune afterwards. So the Chilton/Haines manual is okay?
     
  6. ttocs

    ttocs Legend

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    definitely upgrade to some nice bolts as it only takes on broken one to really F things up. While you are that deep into it I would do the cam as well and with all that you can probably count on a tune being needed as well.

    I am on the other side of the coin from the guys above. I was having my usual health issues when I upgraded my heads/cam and asked some guys in my mustang club how much they would charge and paid them to do it. They are both long time 302 guys that have had some really nice drag racing cars so a heads/cam swap should be no issue right? Well they were more carb/fox guys and it gave them some troubles getting it all to work. So even people that should know what they are doing can run into issues. At the very least ask around and see if you can find a friend or a friend of a friend that could help. It never hurts to have a 2nd set of eyes especially if they know a little more then you. If its a good friend maybe some pizza and beer or a little cash might not be a bad investment.
     
  7. SLOW95GTS

    SLOW95GTS Active Member

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    As long as your using factory parts like the cobra intake, gt40, what ever cam you shouldn't run into any problems. My first hci setup went in pretty smooth, just took longer than usual because I wanted to replace a lot of stuff like hoses and ect. which rocker arms are you going with? I recommend crane 1.7 roller rockers and you'll still be able to use your stock valve covers. Like ttocs said, its always nice to have friend to help you out, two heads think better than one.
     
  8. MTB'94

    MTB'94 New Member

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    Thanks everyone! I think over the next few months I'll work to assemble the various parts I will need for the install. I was planning to do the GT 40 heads with that TFS stage one cam. I've seen that on several combos and people have seemed to like it better than the Ford cams. I was considering the 1.6 roller rockers. should really consider the 1.7 rockers Slow95gts?
     
  9. MTB'94

    MTB'94 New Member

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    Also, do I really need to replace the lifters and pushrods etc.? I bought the car about two months ago and the previous owner claimed the engine has been rebuilt but we all know how that goes. It does seem to run well with no smoke and the car was basically restored which is the reason I purchased it in the first place. Very clean!
     
  10. SLOW95GTS

    SLOW95GTS Active Member

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    It should run great with the tfs1 camshaft with either cranes's 1.7 or whatever brand 1.6 roller rockers but make sure to change the valve springs on the heads. You dont have to change the lifters or pushrods but its nice to do it if the motor shows signs of wear.
     
  11. RichV

    RichV Well-Known Member

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    I would replace the timing set along the way, as mentioned, belts, hoses, whatever needs maintenance. You'll need different plugs, so get some new plugs/wires, cap/rotor. Obviously fluids like oil and coolant. Maybe check the radiator while it's out for any flow issues, gunk, or damage. Replace it too depending on condition.
     
  12. DavidBoren

    DavidBoren Active Member

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    If you get the GT40 heads from a cobra, they will have the 1.7 ratio rockers... or should. I, personally, think that you should let the cam do the work, not the rockers. If you want faster ramp rates, get a cam with more aggressive lobe profiles, don't try compensate with higher ratio rockers... that is just a band-aid. My opinion, lots will disagree, I'm sure, but that's my story and I'm sticking to it.

    Other than that, what are your goals for this swap? Just to bump it up a bit? A set of cobra pull-off heads will do great, even with your stock cam. The 1.7 roller rockers on the cobra heads will liven up the GT/HO cam a bit, everything still is plenty streetable, and you don't need a tune but it will be a noticeable increase.

    If you refrain from going overboard with new cams and tunes, given that you don't seem to be chasing maximum performance, you can put that cam/tune money into replacing little sh!t that will keep the car running for years. Hoses, ground wires, bushings, timing components, bolts, gaskets, distributor and associated parts... I would way rather refresh/rebuild a motor and only gain 30hp, but know it will give me another 150k miles confidently... rather than blow my budget chasing 50hp instead of 30, and not have money to replace/upgrade all the all-too-often overlooked items.

    I can deal with a weak engine that is reliable. I will not tolerate any engine that I cannot trust, regardless of how much power it makes.
     
  13. MTB'94

    MTB'94 New Member

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    I do plan on replacing the timing gear/chain set along with other worn parts that I may find. The car is actually in VERY good condition and many parts are new. My guess is I'll just need the various head bolts and gaskets etc. to make it right. Like you said DavidBoren I'm not looking for Max power mainly because my wallet will not support it! LOL. Being the car already has a CAI, 70mm TB, Cobra upper/lower intake, full O/R exhaust my thought were the GT40 heads would mate right up with no hassle (or so I've read) and I should somewhat be able to maximize what I have now. I'd also plan to swap the mass air meter for a larger one so everything is opened up.

    My first Mustang was a '95 GT with similar setup but factory long block and even though it sounded great, and was fun to drive, it was a dog on the track especially compared to the '01 GT I bought new after selling the ole 5.0.

    I feel like if I swap the heads to GT40's, throw in the TFS stage 1 cam with some 1.6 rockers, and get it tuned I should have a decently quick car for street fun. I don't plan on doing much, if any, drag racing.

    Also, I do want the cam if I'm going to be pulling the engine down anyway. The cool factor is really enough of reason for me to have it. That's why I was thinking I'd need 1.6 rockers instead of using the 1.7's if I did in fact get the factory Cobra heads. Isn't that correct thinking? I didn't want to have piston clearance issues.

    Oh, and it definitely will have to be 100% reliable!
     
  14. MTB'94

    MTB'94 New Member

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    [​IMG][/URL][/IMG]
     
  15. MTB'94

    MTB'94 New Member

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    There's the car in question. Just remembering how to post pics on message boards lol!
     
  16. MTB'94

    MTB'94 New Member

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    So what do I need to look for when buying a set of used GT40 heads? Is there anyway to tell if they are damaged really?
     
  17. OnyxCobra

    OnyxCobra Legend

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    Do you just want the cam for sound or do you have a power goal in mind? Stock Cobra setup with bolt ons and tuned right is good for 250+ whp. In my opinion if you go with stiffer valve springs you should go with hardened pushrods also.

    I'm not really sure about the heads, it seems like cast iron heads would be hard to damage lol
     
  18. MTB'94

    MTB'94 New Member

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    Lol I know the irons are tough I just didn't know if there was anything visual to look for that may make them not worth the buy. The cam....umm yeah I probably want it for the sound but I'd hope there's some power to gain over the stock...no?
    part of me just wants to bite the bullet and save up for the Trick Flow complete top end. Seems like when you factor in how much comes with it the cost isn't so much.
     
  19. OnyxCobra

    OnyxCobra Legend

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    the cam is easily the best part of the stock setup, the classic example is the 400+hp they made with the stock cam and AFR heads.
     
  20. tykempster

    tykempster Member

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    B Cam is cheap and has a nasty lope if that's what you're after. Certainly gains some power up high, but I've heard there's better cam designs. I went with the B cam though...cause that idle: https://www.youtube.com/watch?v=x06_QuhqwCw