5.3 truck engine converted to 5.7 LS1

Discussion in 'High Tech Retrofits' started by ctchap70, Jul 24, 2011.

  1. JohnnyZ

    JohnnyZ Veteran Member

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    Here is what I have found out about the 5.3l swap in my efforts.

    I purchased an engine from LKQ last spring after reading for weeks build threads and faqs on LS1tech and this site about various LS based swaps. There is an FAQ on LS1Tech highlighting how inexpensive it is to swap the 5.3, referencing a cost of ~$1,500 or so. This is simply not true and would only be feasible in classic trucks or large 50’s boats.

    A few notes in regards to the 5.3 and the 2nd Gen F-body.

    Stock Iron Exhaust Manifolds will not work. They come to rest on top of the frame rails.
    Stock Accessory Brackets will not work; even if you play to run carb manifold.
    Stock Oil Pan will not work; it hangs nearly 4 inches below the cross member.
    *
    Also, please note LS1 parts are EXPENSIVE.
    *
    I have not found conclusive info if F-body manifolds will fit, some believe a 1998 set will, but I’m unwilling to spend $200 to find out.

    Edelbrock was the only company making manifolds to work in the Camaro; they retailed at $500 and are no longer in production. I’m guessing everyone else is having custom manifolds made.

    The Oil Pan, Accessory and Header issues have been personal road blocks and issues of pure aggravation and ire. I find $400 aftermarket accessory mounts to be absolutely ridiculous, especially when many of the options are not guaranteed to work, also paying $1,000 for new GM set is further self defeating. LS1 oil pans are also expensive $300-400 last time I checked for the various new options. I was really hoping the headers would work as well, now I’m left with buying some junk eBay headers and hoping I can heat and bend them to clear the frame rails.

    For the Accessories, the current plan is to mock up some brackets and use a newer Alternator and a classic PS pump. I’m still not sure what I’m doing, I’m hoping to avoid replacing the truck water pump which would be another $300 dent.

    So here is my cost break down thus far. I’m sure I’m forgetting a lot of little stuff.

    LM7 5.3 - $600
    Eddy Carb – Free
    Eddy Manifold -$300
    MSD Ignition - $350
    Jegs Fuel Pump - $100
    Fuel Reg. - $30
    Fan CTRL - $25
    CV Fan - $55
    TransDapt Mounts $45* (utter garbage)
    Flexplate + Adapter - $65 (Came with Bolts)
    TH350* - Free
    Starter - $125

    $1,695

    I still need..

    Headers - $200-600?
    Oil Pan - $300
    Alternator - Free - $150
    PS Pump - $50-$150
    Brackets $50 – $400
    Waterpump – Free to $300

    $600 to $1,900

    Grand Total $2,295 or possibly $3,595.

    If I had gone with a complete LS1 pull out, I would have been able to utilize everything on it with exception to the exhaust manifolds. So while it may have been $2,500-$3,000; it would have only been another $1,000 to get it installed
     
  2. Prototype4342

    Prototype4342 Veteran Member

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    I have heard that LS1 swaps usually end up being around 5 grand when done right. I can say that if I was going to swap to a FI engine I would go LS1 or at least the 6.0 Vortec engine, might as well go big or go home.
     
  3. schitzo

    schitzo Veteran Member

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    Yes that thread has mislead a lot of people and is mostly rubbish.

    I can confirm that F-body manifolds will work for a LS1 swap in a second gen. They worked in my 71. You can pretty much get them for free. Another manifold worth trying is the one out of a 5th gen camaro.
     
  4. JohnnyZ

    JohnnyZ Veteran Member

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    Any 4th Gen or just the 98?
     
  5. schitzo

    schitzo Veteran Member

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    Weren't they all the same? Mine were out of a 1999 camaro.
    These are the exact ones I used. I just had the EGR ports cutoff and welded shut
    [​IMG]

    Here is a pair of 1998 manifolds for sale on LS1tech and they appear to be similar to mine.
    http://ls1tech.com/forums/parts-classifieds/1477068-ls1-exhaust-manifolds.html

    With the numerous number of factory LSx manifolds available, you should have no problem finding several that would work for you. Often times, most people get rid of these when they get headers which means you can find them for very low prices if not free.
    This thread has some good pics of the various manifolds.
    http://ls1tech.com/forums/conversio...ered-late-model-nissan-300-zx-aka-z-32-a.html
     
    Last edited: Jan 3, 2012
  6. JohnnyZ

    JohnnyZ Veteran Member

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    Well i just bought some for $40, we'll have to see how these turn out.
     
  7. schitzo

    schitzo Veteran Member

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    I was able to dig these up from 2006. They should give you an idea of how the manifolds fit
    [​IMG]

    [​IMG]
     
  8. ericmeyer

    ericmeyer New Member

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    5.3 to 5.7L info

    I don't think the OP is still considering this but I wanted to share the information anyway since I was considering the same thing. The reason I was considering this is that to properly unshroud the valves, a larger bore size is always better. Stock LS1 heads have larger valves than the 5.3L heads (I think) and I've seen stock LS1 heads sell for $100. I was going to bore the 5.3 to a 5.7 and build the engine using forged pistons since I'm building a twin turbo. However, when one considers the expense of building the engine compared to using the 5.3L stock, the junkyard takeout 5.3L is the way to go. And if you break a 5.3 you just go get another one. Anyway, here's the article and what they say about the cylinder wall thickness. EM

    http://www.enginebuildermag.com/Article/1091/tech_notes.aspx

    "If it's determined a larger oversize bore may be required to repair a particular block, an alternative should be considered. The 5.3L cylinder block has very thick cylinder walls, which is uncharacteristic of modern lightweight engines. It has been determined by ultrasonic testing that sufficient wall thickness exists to allow an overbore size of the LS1/LS6 GM engines. The bore size for those engines is 3.8970-3.8980"(98.984-99.009 mm), which is an increase of .120"(3.00 mm). "
     
  9. DirtyScotty

    DirtyScotty Veteran Member

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    I put a 5.3 in my 80 Z28. I have the truck accessories except for the A/c compressor which i am pretty sure would bolt up but i dont have a/c. So i used a pulley for a unit without a/c. I bought the engine for 700 with the computer already set up for no emissions and no transmission. My friend and i installed the engine. The engine mounts that bolt to the engine are made by a company called Early Classic. I have never heard of them but they came with the engine and are not offset. The go over the stock clamshell mount on my 80. The engine sits farther forward in the engine bay than a typical small block chevy but it worked out cause i put a 700R4 behind it and didnt have to shorten the driveshaft.
    The stock p/s pulley will contact one of the p/s bolts on the top of the p/s box. What i did here was i used a p/s pulley from a 2000 grand prix 3800 engine. Then ground a bit of the p/s box bolt head down. It clears now no problem. I had to use a smaller serpentine belt, cant remember the length but if you are in good with a parts store then take a couple that are close to the same size and whichever one fits best you use and return the others.
    You can use a stock 5.3 fan for cooling but i am going to mount the twin electric fans from the same grand prix that donated the p/s pulley.
    As for the manifolds, i spun mine around and turned them up but i am also doing a turbo setup so they wont work for you unless your also doing turbo setup. I am sure there are some that would work though. If not there are headers as an option.
    Next, the oil pan. Yeah, my car is lowered so at first with the truck pan on, everytime i would go in and out of my garage the pan would hit the lip where the garage floor meets the driveway. Its only a little over an inch too. What a fackin pita. I couldnt take the car for a test drive for a long time cause of this. If i did i am sure the bottom of the pan would have ripped off. Soooo, what i did was i bought another truck pan from the scrap yard for about 50 bucks and the fitting i needed for the turbo oil return as well as a bung for a drain plug. My friend and I measured where the pan needed to be, depth wise in the sump, to clear the crossmember on the car. We basically measured the portion of the sump that had to be cut off the be able the clear the bottom of the crossmember. THis way obviously the crossmember will be lower than the pan. We sliced the bottom of the scrap yard pan off at the desired depth. It ended up being about 2.25 inches from the outer bottom of the pan to the cut line. Once that chunk was cut off i went and bought a piece of 1/4 inch aluminum plate and then cut the plate to cover the bottom of the pan that had been cut off. i used a sawzall and jigsaw and well as a carbide bit on an air grinder to get the desired shape. Then i cut a hole for the bung for the drain plug and one for the turbo drain. I cleaned the scrap yard pan and took it to my local tig welder and he welded the bottom on as well as the two bungs. I was worried about oil capacity but it still holds about 5 1/4 litres of oil. And it was cheap compared to paying 400 or so for an aftermarket pan. It took a bit of work for the plate but i saved alot.
    My turbo isnt on yet but i have very little invested in the setup and i have the hotside close to being formed for the turbo. I just have a couple small mufflers on the pipes to quiet the engine down until the turbo gets mounted. It runs good.
     
  10. dcart1

    dcart1 Veteran Member

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    Hot Rod did this a few months ago. Could save you time and money.
     

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