Engine 351w Swap Question

Discussion in 'Fox 5.0 Mustang Tech' started by joetrainer31, Aug 12, 2013.

  1. I can see how the A9L would be tempting if a tune is not going to be used.... but all these equal (with a chip), the 95 cobra computer is a better ecu.

    some info on the 351w swap... written for the fox body, but most is still relevant...
  2. Cool! Thanks for the link. Whatever I do I do not plan on getting a tune. I know, I know, im leaving HP on the table, but so does the factory. Im okay with that to an extent. Besides a friend of mine ran the 95 cobra ECM with his 347, crane 2031 cam, Windsor jr heads, and 1.72 rockers w/o any issues. I'm looking for [more] punch, not max punch. Thanks again for the link! It is very helpful.
  3. Im curious. I've been thinking about your reply. Lets say I nix the 351 idea. If I stick with the 302 and the extras I already have, would I get more out of a custom cam like we were talking about, or a nice programmer? I'd like more torque and smog passing either way. What's the best bang for the buck and would either a custom cam or programmer lend itself to the y303 heads?
  4. I can tell you my 369 made 407 rwhp with the factory A9L computer with no tuning, and 425 rwhp with an SCT chip. The difference can be all over the map depending, but the A9L computer is pretty adaptable.
  5. That's helpful information, reldla. I've owned several cars w/A9L ECMs before. I know how adaptable they are. I have a few of questions for you.

    1) whats a better bang for the buck; 351w with my existing bolt ons & no tune, or a 302 w/my existing bolt ons, tune, and custom cam (or 2031 cam)?

    2) do you remember your torque gain when you tuned your car.

    3) do you recommend a pre-programmed chip, or buying a tuner?
  6. I don't remember the torque difference. I don't remember either being a big difference. I was surprised to learn that I could have driven the car without a tune at all, even with 67 more cubic inches. Better bang for the buck, you'll have to decide, and price the costs for the various pieces and parts for both options. It's a tough choice to make, I thought about it quite a while myself a couple years ago. In the end it's probably too close to call and you follow your heart's desires, at least the ones you can afford and don't' get you in trouble....
  7. I would not bother with a pre-programmed tune, if you're going to do it, go find a local tuner with a dyno to do it right.
  8. Ok. I hear you. I'll nix the pre-programmed chips idea either way. When I said "tuner" I was referring to something like a Moats (spelling). You know, something that I program myself. Would you still go professional tune above programming at home?
  9. Why not port the GT40's and put them on a 351?
    That way you get the cubes you want, get some decent airflow from the heads, and you would achieve the whole idea you're going after.
  10. Good point, 88LX5.0. I'd have to get them professionally ported because I have no experience doing that. I just take parts off & put other parts on with a little diagnostic on the side. Therefore, I have 2 questions:

    1) is it worth the cost to pay someone to port my heads, or should I sell them and put the money towards other heads?

    2) if I port the heads, or buy better flowing Ford heads is a different cam still needed? In other words, will better flowing heads necessitate a bigger cam? Please, keep in mind that I'm not trying to squeeze every ounce of power out of the combo. I want decent extra power, LONG term reliability, and smog passing.

    You all are so helpful. Thank you for the input. I really value all of it.
  11. Well, how many miles are on the current heads? I ask because if they're high mileage, you'd probably wanna rebuild them. So rebuild cost and machining costs would probably put you close to aluminum headed territory but you wouldn't have the same gains as aluminum heads. You'd save some money, but you'd still be sacrificing some HP. But if you're okay with doing that to go with how you want the car, then go for it. Also, you don't NEED a different cam. But without a doubt, a custom grind cam is going to be a great upgrade for any combination.
  12. 1) The heads and motor have about 60k miles on them. At the same time they are original to an 18 year old car, if that makes a difference.

    2) I can get aluminum heads rebuilt and fully loaded for about $450 a pair.

    3) How much would a typical custom cam cost, considering the mild build im looking at? If its a lot, maybe I'd be fine with a 2031 cam. Those aren't too expensive.

    Thanks again for helping me think this through!
  13. Custom cost about $330, last time I priced a 2031 which is now called 444225 for a customer was about $350

    Sent from my XT907 using Tapatalk 2
  14. Wow. I had no idea. That's really helpful. Thank you!
  15. The 351 will be stronger than any stock 302 block wise. More costly and have clearance issues but make more power. If budget is the word do the 302 and have a fun runner. I've built a 351 before... In now going or staying 302 based.
  16. Thank you for your input! Can you please help me understand what you mean by, "clearance issues?" Do you mean hood clearance? If so, I have convertible motor mounts and a 96 cobra hood. Is that sufficient for clearance?

    The expense I understand due to the initial set up. I'd appreciate any further input you may have.
  17. Even with the very mounts and cobra hood it will be though to fit. I've gotten a fuel injected 351 under a stock fox hood but I'm not sure what it takes on a sn car.

    The headers will be tight against the sides and trans.

    You just need to decide on the use you're going for. Just a fun cruise stay 302 but if you're after power the 351 will live longer but requires more.
  18. Thanks man. This is helpful. It sounds like I should stay with the 302 as much as I like the idea of a 351. I think its only because I've never had a 351. So this leads me to another question:

    Since I'll stay with a 302 I'd like to know how much further I can push my 19lbs injectors. I currently own an SVO GT40 model that came with GT40 heads, intake, crane 1.7 RR, 65mm TB, under drives, and 373s. There is a flowmaster catback added to this combo. Obviously my injectors work now, but if I were to add aluminum heads or better flowing cast irons (maybe Windsor Jrs) for more power, would the 19s be pushed?
  19. A nice aluminum hci car will work with 24s but if your spending money you just as well leave room for improvements. I'd go 30s at least and just dial them back a bit.
  20. Ok. Seeing that I'm interested in more power, but not at the expense of longevity or reliability, I'm thinking of reusing my SVO intake and stock camshaft. Maybe just add a set of nicer heads. I don't want any idle issues or CA emissions issues. Any thoughts?