Building A 331 Stroker.......advice

Discussion in 'Fox 5.0 Mustang Tech' started by sundown_2004, Jun 5, 2013.

  1. i am currently looking at building a 331 stroker for my mustang. I currently have a 93 cobra intake, f 303 cam, shorty headers, 4 10 gears, TKO 500 5 speed with king cobra clutch, 70 millimeter throttle body all calibtated to the stock 5.0 block with the cam in it (f 303), what am i going to need to make the block run right. I am also buying a set of tfs heads (possibly the r series head). Any advice on this would be greatly apperciated.
  2. If you want to make power and keep up with Coyote 5.0's...start with a 351 based platform.
  3. I like the look of the cobra/gt40 tubular, so if you do as well and want to keep the cobra intake. You need to get it ported/polished VERY well to really get any use out of the 331 cause that's gonna be your weak point no matter what head you put on it. Some like the cobra more because you can actually port it better because of it's cast design and not tubular design like the gt40. They say the unported cobra/gt40 tubular is good for 350hp--ish, but IMO, I feel a VERY good port job with the right cam/head combination I think could do 400hp.
  4. I have been looking at the DSS 393 stroker motor combination with the tfs r series heads. or a 347 combo to keep the engine under the stock hood. i am at this point a little worried about switching to the 351 block foundation due to the amount of mods need to get it in. But i am open still either way. Anyway, what does everyone think of either engine at this point. im looking to get serious power (500 plus horsepower) i keep seeing alot of engine combos online that claim such power from a naturally aspirated engine. i have a ten pound paxton supercharger sitting around as well with the rest of the parts that are in the car. I want aproven combo that isnt a brochure for a magazine, and looking for some reliability from such a set up.
  5. Also, before this progresses what company would you purchase your motor from? I hear alot of people talking about fordstrokers , what about D.S.S. racing as well? Remember i have a superchager as well........
  6. Believe it or not, there aren't to many changes you need to do if you're staying EFI. Trust me, I have a nice DSS 331 motor, but in 2013, 400 HP doesn't seem all that much. If I were to buy a 351 based long block, all I'd need to change is the intake. Everything else will work; injectors, throttle body, mass air, just about everything.

    Also, 500 HP N/A would be a starting point with a 351 stroker motor. Hell, Ford sells a crate engine 427 that makes 600 HP N/A.
    sundown_2004 likes this.
  7. True enough, what about the motor mounts, front coils (i have a beefed suspension), and other stuff needed. There has to be more to this swap. what about a 408 stroker block? It sounds like i need to do research.........
  8. From what I'm hearing, and reading...minimal modification, if any, is needed.
    sundown_2004 likes this.
  9. Whether you go stroker 331/347 or 351 swap,
    ...really look at what you want to do as far as N/A or Forced induction. That direction is going to lead in your piston/heads being prepped, bigger chambers for the forced induction or milled heads/deck for higher compression on an N/A set up. That will be key for the kick in your ass difference on either set up. :nice:
  10. to go 351 based you need a fox pan , 28oz balancer and flywheel , accessories swap over and you need a 351 deck intake , 408 is just a variation of a 351 with a stroker kit ,

    Sent from my iPhone using my fingers
    sundown_2004 likes this.
  11. Im still going to need a hood with how much clearance for a 408. The computer will need to be chipped or tuned. how about exhaust i have a full exhaust for my previous setup? Full flowmaster set up with shorty header (bbk). I mean this is not going to be as easy as i hear. Or is it? N A motors are awesome but i do have the Blower, should i sit it on the bench? The motor has a custom mass air in it as well. It was tuned already, i also got lucky today and decoded my tremec transmission as well i have a 500 ft lb unit. my rear axle has been built as well from what i see. Subframe connectors the whole nine. I am sure glad i went with a 5.0 that was modded already. Looks like im gonna go with a 351 stroker then for now. Now how to get it in there with no real problems.

    As far as the blower set up, i understand the concept of volume metric efficiency and the idea of using a dished piston with a larger combustion area. Seems like a alot more effort for the blower set up than im willing to deal with for the moment.

    Keep the comments coming guys, by the way thank you all for your posts and comments. I nice to not be the only ford guy that knows something. The locals in town around here are not very friendly to ford guys to begin with. Its mostly ricers and jerks with new cars with alot of money but no real skill around here. I am a 5.0 vet, been in it since 1990 when i got my first 1979 5.0. But i just never got the chance to build a real wild car. I finally have my chance and have a really good starting point cat and a large budget to work with. Got the garage, tools, alot of time, and finally a good friend who can wrench as well around.

    So i need to know the real difficulties in putting in a stroker 351 into the car? Also who should i go through to buy the long/short block and what kind of heads would all of you go with? Let the debate begin.

  12. Ok but will the 5.0 pan work? and will the flywheel work as well? What about the aftermarket heads for the acessories. I am also using an electric fan. Will my cobra intake be enough for airflow for 6500 rpm? If not what intake to go for?
  13. Your 302 Cobra intake will have to be changed to a 351 Cobra intake.
  14. Meh, he shouldn't have any trouble keeping up with stock and usual bolt on Coyote's with any of the 302 based strokers either.

    My 331 combo is nothing special and am sure it'll run door to door, or better with a bolt on Coyote. The OHV 302 may not be sporting the technological advancements of the newer iron, but one thing us Fox guys have going for us is the weight advantage. My coupe is tipping the scales at around 2,850lbs. That puts me about 500lbs lighter (or better) than any S197 out there.

    While you're correct that 400hp isn't anything special by todays standards, when you consider a Fox body can be had roughly 400-500lbs lighter than the current Mustang GT and anywhere from 700-1,200lbs lighter than the GM and Dodge offerings, hearing a number like 400hp quoted with these modern muscle cars doesn't impress me as much as it used to. :shrug:
    89stang1 and sundown_2004 like this.
  15. True enough. I should've said, "be in front of". For at least 4-5 years I was easily in front of new Mustang GT's with my car. Not so today with the new Coyote 5.0's

  16. There is a very complete write up on 351 swaps on this site. I am on my my phone so you will have to look it up. But I think you will have to use the right distributor and it tells what pan to use. I am in the same boat, minus the blower.
    sundown_2004 likes this.

  17. The reason you are faster than the coyote ugly cars is because you have a far better power to weight ratio. Also, those cars wont be as easy to modify and a far more expensive to mod because of the advanced computers in them. Dollar for dollar i would put my money on a 5.0 or windsor block because of the ease of modification compared to the new 5.0 block. Plus those coyote engines cannot be stroked to far out without spending the big dollars on a new block from ford. I cite 5.0 mustang as my source on that. They are also a nightmare to tune. those cars are just too expensive to tune and build right now. Also there is the problem of having to tune the motors everytime you change any part of the engine or anything that messes with air flow into the engine or fuel. This is due to the extreme control over the fuel delivery and timing of the ignition of the intake charge. This is due to the extreme air to fuel ratios the coyote motors run at lower loads and rpms (40 to one if im right at some points). So you cant imagine the extreme AMOUNT of processing power and control over the engine to accomplish this. Anyway 5.0 forever..............
  18. they make a 351 swap pan . As I said you need a 28oz balancer and flywheel because foxbody is 50oz balance and no I do not think your cobra will breathe enough but that depends on the rest of the combo honestly

    Sent from my iPhone using my fingers
  19. either way even if you went 331 you'd want a 28oz balance which would mean you need a fly wheel and balancer any way because at 50oz balance the crank looks like Swiss cheese and that's not cool

    Sent from my iPhone using my fingers