Stroke Existing 360 or Buy 408 Stroker?

General Mopar Tech Discussions

  1. Evoking

    Evoking Well-Known Member

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    I am wondering what the general consensus is. Is it cheaper to buy a 408 stroker kit for an existing 360 or buy a stroked block and transfer over all components?

    Obviously more labor to stroke the existing engine. But the kit is only $1200-$1800 internally balanced. A crate would run $5200.

    Also what are the pro's and cons?
     
  2. PurpleBeeper

    PurpleBeeper Well-Known Member

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    I've been thinking about this same issue with big blocks. IMO, it depends a lot on your engine building skills & if you feel comfortable assembling a short block & valve gear + your skills at clearancing a block for stroker interference. It obviously can save money if you can do it yourself and since I'm seeing less & less machine shops in Chicago balancing engines, the "kit" has another advantage in my mind.

    If you buy the whole motor, just drop it in. If you get a long block, then carbs/intake/ignition are your only issues. For a short block, you still have to set up the valve gear (centerline cam, pushrod length, rocker side-play, etc.). Assembling your own block, all the tolerances are up to you..... crank endplay, cutting piston ring gaps, clearancing block, installing crank/pistons/rods, checking piston-valve clearance, etc.
     
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    • Yatzee

      Yatzee Well-Known Member

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      I agree with Mr Purple because a crate engine should come with a warranty in the event of flaw in the power plant. If your not adept at engine building I don't think it's time for a "day of discovery", the crate builders do this kinda work all the time, and have already discovered the pitfalls of their first generation engines. You'd probably end up spending the same, or more, doing it yourself with no safety net for personal screw ups. But then there's the challenge of building your own power plant so if you can afford to lose some cash ( maybe twice ) go for it and build it yourself. You'll only have yourself to hold accountable in the event of a mishap. Just the tools and equipment to do a quality build can add up to a huge amount - decent gaskets and bearings, assembly gauges and measuring devices, ring grinders, quality torque wrench, new bolts, machine shop charges and the list goes on.
       
    • FlagCraig

      FlagCraig Well-Known Member

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      I stroked the 340 in my 72 Challenger to a 416. The two main reasons I did was it was my father's car and important for me to keep it original. And it was a good learning experience.
      If you have no emotions in the hunt nor originality a key factor then a crate motor needs to be weighed heavy in decision. Overall cost and warranty as mentioned above is a huge plus. I would go as much HP as the car can currently handle and play hardball.
       
    • the mississippi madman

      the mississippi madman Well-Known Member

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      I can't find any pros for spending 4000 more bucks on the same thing if you already have a 360 block to work with
       
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      • kiwigtx

        kiwigtx Henchman #4 Staff Member FBBO Gold Member

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        I agree here, as long as the components you have are all worthy of using in the sawp - block included.
        I have thought along the same lines myself for upgrading my A100....after all, the chances of fitting a blown HEMI in that are gradually fading. :)
         
      • moper

        moper Well-Known Member

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        IMO there's really five factors to consider:
        1. Goal - how powerful do you want it to be? What fuel type? What sort of use will it get (cruising, racing, road racing, etc).
        2. Budget - how much money do you have for the engine? For the rest of the driveline and any other mods to attain your goal?
        3. Skill level - what can you do yourself?
        4. Inventory - what do you have for parts already on hand?
        5. Timeline - how much time do you hace to get things done?

        Goal drives what has to happen.
        Budget drives what you can afford to do or have done - make sure you are honest with yourself here...
        Skill level is how comfy are you with doing things? Do you have the room, the tools and equipment, etc?
        Inventory is what can you reuse? Do you have stuff thats strong enough or unworn enough to keep leaning on?
        Timeline is just that. If you're starting in February and need it for April 1, and need a 600hp monster - you better find something on a shelf.

        Personally - I do everything except machine shop machining. I have a very good shop for that stuff (read as not cheap). I have seen a lot and have very little faith in crate engines. That comes from being an ASE Master tech years ago, moonlighting in a machine shop, having fellow enthusiasts to talk to, and the internet work I do. Price shopping is simply not a good idea. Nor is assuming a warranty actually will cover what you expect them to (they don't - typically).
         
      • Evoking

        Evoking Well-Known Member

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        All great points. I have no experience. Was going to have my shop do all labor and manage machining. More risky and potentially costly due to labor costs. Will go crate.
         
      • hunt2elk

        hunt2elk FBBO Gold Member FBBO Gold Member

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        I am debating the same thing on my current project. What kits are you looking at in this price range?
         
      • Superb Bee

        Superb Bee Well-Known Member

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        Plenty of small mopars for good prices... Blue print 408 with iron heads is around 4300 shipped, with aluminum adds like 700. I have seen them all the way up to $12K, sd engineering will build you one like you couldn't imagine (500 race ready hp) but your check book wont be happy afterwards...

        I think if you have a good block, it would cost you - 1400 for stroker kit, $600 for oil pump, gaskets, rockers, cam, lifters, pushrods, timing set, oil, etc, 1700 for decent aluminum heads, and $300 for an intake.
        then $500 to machine your block, boil, blast, mag, bore, hone, f-plugs, cam bearings. And $500 to assemble it...

        So $5000ish and a bit of leg work, I would get one built but I have an awesome builder and the last small block we did we stroked 360-408, with a roller cam, mopar performance cast iron heads, scat stroker kit. Cost was around $4000 but we scored the mp w9 heads for $750 for the pair brand new stripped (part number was complete someone needed the valves and springs I guess), I also found a complete lunati roller setup that came with cam, lifters, timing set, etc the summit racing price was like $1200 I paid half of that, brand new in the box at a swap meet..


        So if not in a hurry, I say shop around, put the feelers out there, wait for the deals to come, BUT if you are in a hurry, get the crate.. Looking for a deal on motor parts is hit or miss, I buy the parts as I see them for a price at or below half cost as long as they are usable to what I do and not full blown race.

        I have 6 sets of 383 and 440 pistons on the shelf, all brand new, some day I will use them, I got great deals on them from machine shop shelves, craigslist, etc.
         
      • rumblefish360

        rumblefish360 Well-Known Member

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        Here is an honest question that needs you to be honest with yourself about the prospective build at hand.

        What is the goal?
        Driver? Street stripper?

        I like doing things myself. It isn't really hard but you'll need room and time to build your own engine.
         
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        • moper

          moper Well-Known Member

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          If you consider "your shop" a risky proposition, you really need to rethink a crate engine where you have nothing to go on, no first person presence, during the process. Your location shows as in Dallas. There HAS to be a highly reputable within driving distance of you. Find a shop you trust and have them do it. The biggest names in "Mopar specialists" I don't trust based on personal experience. If you can't find closer I'd look at Jim (IQ52 here), Indio Motor Machine in CA, Mike Liston at MRL in MI, or Bob George Racing in OH. All are simple Google searches. None of those are "crate engine specialists" or the cheapest out there but all will do a high quality job and personalize it for you.

          I'll add - if you are looking at a figure of $5K for a 4" stroke Mopar small block, honestly dyno'd (not a representative dyno sheet provided), and ready to go with some form of warranty you're probably not considering all the pieces to the puzzle. I build fairly cheap. I couldn't do it for less than $8K using quality parts, prepping everything to a high level of quality, and actually getting it on a pump to break it in and verify everything.
           
        • SublimeSixpack

          SublimeSixpack Well-Known Member

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          Buying a crate engine can be a crap shoot, same goes for having someone build an engine for you. I have one crate engine and it's been fine but it was a new engine not a rebuild. I have rebuilt engines that have been fine, and others I've had issues with. I'm at the point now where I have a shop do the machine work, I then check their work to make sure they did it correctly, then I assemble the engine myself. Continue to do your homework then decide what's best for you then go for it.
           
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