94 gt stock heads-to use or not use

Discussion in '94-95 5.0 - Specific' started by 94OJGT, May 2, 2007.

  1. 94OJGT

    94OJGT New Member

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    should i port/polish my heads
    or just
    save and buy new heads?
    cause im planning on gettin F/I on this thing after i find a old 351 that i can swap

    and 302 heads fit on a 351 right?
    soo.....if i buy new heads which would be good for forced induction
     
  2. ryclef331

    ryclef331 Well-Known Member

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    NO, Stock 302 heads will not fit on a 351 unless you drill out the bolt holes. 351's use a thicker head bolt. Running stock E7E's....even ported...will CHOKE THE HELL out of any 351.

    As for aftermarket heads, they come drilled for 351s. You just need the correct washers (available from trickflow, edelbrock, etc) that drop the head bolt holes from 7/16" to 1/2"
     
  3. 94OJGT

    94OJGT New Member

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    yea i know stock 302 will be shit on a 351, but i forgot to specify that ill be using this stock 302 for a while before i find a 351w for a turbo set up i plan on doin in the next yr n a half, i just wanted better heads for the time being, and i now realize that it will probly be just a waste of cash to port/polish stock heads, so....yea...lol
     
  4. 94OJGT

    94OJGT New Member

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    and while we are sort of on the topic....

    which 351w block yr would be best for over 600hp

    im tryin to find a block capable of 600-700hp reliably
     
  5. Downshift

    Downshift Well-Known Member

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    There is a 351W swap thread in here somewhere. The older blocks are stronger and if you can find a mexican block those are even better. Only problem is if you wanted to run a hydro roller cam in anything pre 94 block I believe you will need to get a convertion kit from summit or somewhere. Other wise its flat tappet.
     
  6. Paul

    Paul Legend

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    6-700 horsepower is a lot for a stock (older) 351 block but is manageable if your tune is good.

    I wouldn't bother with your old heads. I have a 422 stroker in my car, and if I can give any advice to anyone doing a 351W (especially a stroker) swap it would be BUY GOOD CYLINDER HEADS.

    If you think they're too big, they're probably just right. A set of AFR205s would be perfect for a mild windsor stroker. AFR225s are good for a little more rowdy one. I have Brodix M2 Track 1 CNC heads on mine and I like them. Make sure you have the intake to match. I run a Trick Flow R with a 90mm TB and 4" inlet pipe.

    Also, you don't need to run flat tappet in an old block. You can buy a hydraulic retrofit cam, and stock hydraulic lifters - you just need to drill/tap the block for the lifter retainer and put the "dogbones" back in. It's very easy.

    Paul.
     
  7. GaryG

    GaryG Well-Known Member

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    some1 correct me if something is wrong in this...

    The 351W is a Windsor class engine. It is made on the same factory line as our beloved 5.0. However, 351's are about 100 pounds heavier than a 302, but the 351 posseses several qualities that make it a desirable block for an engine buildup. The advantages of using a 351W vs a 5.0 (302):

    Obviously, you get an extra 49 cubic inches of displacement. As the saying goes, there is no replacement for displacement. Second, the webbing in the lower half of the block is thicker, making the block stronger. Third, the crank has bigger main and rods journals, making the cranks more durable than their 302 counterparts.


    FACTS: What you need to know/consider when you swap a 351W:

    The 351 block is very similar to the 302. That means that almost all parts swap between a 302 and a 351. This includes: Heads, cam, lifters, timing chain, timing chain cover, water pump, engine mounts, and all sorts of other stuff. The bellhousing bolt pattern is the same as a 302, so all trannies that bolt to a 302 will bolt to a 351. However, there are some differences in the 351 that necessitate new parts:

    1) The oil pan is different. Motorsports carries one. You can also get an oil pan of of an early eighties LTD Crown Vic. If you go the junkyard route, remember you also need a oil pan pickup tube, and a special main bolt that the pickup attaches to. The FMS pan is a pretty good deal, and if you shop around, you can get one for under $100, which comes with the dipstick, bolt, and pickup tube.

    2) The internal balance of a 351W is the same as pre-81 302's (28.2 oz). The 5.0 HO has a 50 oz. unbalance, which means you cannot use the flexplate/flywheel or the harmanic balancer off of an HO engine. You have to get the correct pieces from a dealer/junkyard.

    3) The deck height is higher, which means you need a different intake, since the 351W intake is wider. A 5.0 Upper will bolt to a 351W lower.

    4) Also, a higher deck height means that the accessory bracket will need to be replaced. FMS sells the new bracket for about $50.

    5) The higher deck height means the headers sit up higher than in a 302 powered Mustang. A special set is required for a 351.

    6) A 351W will not clear the stock hood, unless you get convertable mounts which will lower it roughly 3/4". It all depends on what intake you use.

    7) The distributor has a fatter shaft. You can obtain one from a 351W powered FI truck (if you are using FI) or any late 70's/early 80's car using the 351W and a Duraspark system if you are going to build a non-efi car.

    Those are the major differences. As you can see, for about $1000 you can put a 351W in your Mustang. This is cheaper than a stroker, plus you wind up with a more reliable engine.


    Tips: There are several things to look out for to ensure that your swap to a 351W is easier and more successful. They are as follows:

    1) A high volume oil pump WILL NOT clear the FMS pan. If you want to run an HV pump, you must either modify the pan, or buy a Canton or similar pan, for many dollars more. The modifications just include cutting down the front drain bolt, and welding on a corner to the pan to clear the pump housing.

    2) Get new motor mounts. If your mounts are questionable already, the additional weight of the 351W will make them fail in a hurry. I recommend the 87-93 convertable mounts, which will work in any 79-93 Mustang.

    3) Also, with a HV oil pump, be sure to have a 7 qt pan, otherwise, if you spin it high for extended periods your gonna run the pan dry and spin the bearings. Crank scraper/windage trays work well.

    4) The '69-74 351W blocks are most desirable, they will hold alot more power than a '75-93 block. The '69 block has a different deck height than the other windors. 9.5 is the normal deck height, but the '69 is 4.8xx I think. Also when you get to the newer windsor motors such as in the lightnings they use the two bolt main sportsman blocks. But only the ones in the lightning trucks.

    Holcomb Motorsports carries all the necessary parts to do the complete conversion.Website is http://www.holcomania.com/ .. The number 1-800-475-RACE (7223)
     
  8. 94OJGT

    94OJGT New Member

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    so if i find a nice 351w block should i stroke it? or lve it for a turbo set up
    b/c i am making it a TT stang
    would their be ne complications with stroking it and a turbo?
     
  9. Paul

    Paul Legend

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    Stroke it. There's no reason not to. If you're building a motor anyway, you might as well have all the extra cubes. The only downside is the cost of everything. With a turbo 408 you need big heads, big intake, big TB, big everything.

    A turbo 408 will make earth-moving torque.
     
  10. 94 DropTop

    94 DropTop Well-Known Member

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    anything bigger than a 306 just get aluminums. If your change your mind and just want to keep the 302 send the heads to thumper.
     
  11. ryclef331

    ryclef331 Well-Known Member

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    Your wallet gets lighter....thats about the only downside I see.
     
  12. Paul

    Paul Legend

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    ...and your stress level and time spent in the garage increases. :) Haha.
     
  13. 94OJGT

    94OJGT New Member

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    yea......its probly gonna end up being over the 10 grand mark for this build
    good thing i got 18.5k from my ricer i sold lol..( 03 celica trd)...what a hunka crap.
    ive had more fun buying my car smashed and fixing it then i ever had driving that thing