LS engine swap cost/adaptability for 70-72 Skylark

Discussion in 'High Tech for Old Iron' started by Christopher Spouse Drew, May 11, 2019.

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  1. Christopher Spouse Drew

    Christopher Spouse Drew Well-Known Member

    So, I have a 455 that I need to build, starting to do the head work now. Im thinking about total cost and what I want from the car. Reliability, I want to daily drive the car. I want my family to enjoy the car with me and they always say they can't stand the exhaust smell in the interior. They dont get it.. haha. So with the engine cost for the stage 1 conversion on the heads, block work, all the parts, fuel injection. I'm looking at a total of about 3-4K. I'm a mechanic, I can go to u pay u pull and grab an LS out of something.

    So, I want to hear from the guys that have done the LS swap, what LS do you have? Total cost? Difficulty adapting into our cars? Performance? What transmission? Driveshaft? Rear end? Tell me as much as you can so I can make a decision. Thank you guys in advanced. The only thing I do know is, I'm not getting rid of my 455, it will go in one of my future cars!
     
  2. GotTattooz

    GotTattooz Well-Known Member

    I bought a 99 Chevy Silverado with a broken frame for $1300.00. I used the engine (5.3l), transmission (4l65e), steering column, dash cluster and complete wiring harness in my 65 skylark wagon (my build thread is in the Wagon section). I swapped intake and oil pan for clearance (2000 Camaro intake, Holley oil pan), bought an alternator relocation bracket from DirtyDingo.com, Holley motor mount and trans crossmember kit, Holley in-tank fuel pump and some LS swap headers.

    I'm sure I have prices in my build thread. The 5.3l is stock except for the intake and oil pan. I'm running 3.42 gears and I get 18-24 mpg, 285 hp and zero reliability issues. Having the complete wiring harness, I also retained the obd2 port, so I can use a scanner to check for any issues, should they arise.

    http://www.v8buick.com/index.php?threads/my-1965-skylark-wagon.285229/

    -Josh
     
    Last edited: May 11, 2019
  3. docgsx

    docgsx It's not a GTX

  4. 436'd Skylark

    436'd Skylark Sweet Fancy Moses!!!!!

    I can say if you're a decent mechanic there is no reason why the 455 can't be reliable with a carb. It's laughable that folks think anything with a carb will explode at any second... just how did people get along for 90 some odd years with carburetors?


    If you have exhaust leaking into the car you have other issues.. rust holes? Leaking exhaust? Or is it so rich it burns your eyes?
     
  5. docgsx

    docgsx It's not a GTX

    An LS is kind of cool for now, put the big block in there when you’re ready and get a good OD transmission so you can make it a DD
     
  6. Christopher Spouse Drew

    Christopher Spouse Drew Well-Known Member

    I have a very tired 350 in the car now that I wont spend a penny on, its all about the engine I choose to build. I can make the 455 run great, but in the long run, an LS is much easier to diagnose and get replacement parts locally, the gas mileage is better, and it will last longer between rebuilds. and the most important thing to me, the COST! I didnt say anything about carbs blowing up..
     
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  7. dr

    dr Well-Known Member

    Its your car do what makes you happy.
     
  8. cobravii

    cobravii Well-Known Member

    It is your car and you can do whatever you want BUT my thoughts are the same as 436'd skylark. These cars did not have exhaust smells when new. If you want to use an LS engine then get a chevelle.
     
  9. Ryans-GSX

    Ryans-GSX Have fun, life is short.

    Friend of mine put a LS 6.0L in his Buick and loves it for the fact he can drive it on road trips and it does remarkably well on gas milage. He loves it. He paid a shop to do the work. I don't think it was overly hard for them because the kits make it much easier than in the past.
     
  10. Mach5racing

    Mach5racing Well-Known Member

    I would love to swap a ls in my skylark someday. The power and reliability is worth it in my eyes. I think with some careful looking around you could do it pretty cheap. I have a friend with a 55 Chevy with a ls and a 6 speed. It is an awesome car. With just a cam swap and a few other things you could be around 400hp which is perfect for a street car. 400 hp out of a Buick 350 would cost significantly more. With that being said my other friend has a 70 skylark with a 455 and a 4 speed. And that car is awesome as well. It’s a real tough decision. But either way you went if your not happy it can always be changed in the future.
     
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  11. GraySky

    GraySky Well-Known Member

    It's a tough decision. Every time I think about the pros and cons of using an LS engine, I think it's the best logical decision... but it's just not original, and I can't bring myself to do it. Everything has an LS these days.
    If you compare the cost between a 500hp LS and a 500hp BB Buick, there's no contest (at least when you're thinking without any brand loyalty and just looking at specs):
    LS- good oiling system, roller cam, EFI (this IS a big plus), STRONG block, short block that holds up to 800+hp stock, good flowing stock heads, easy bolt on and control for an automatic overdrive, tons of aftermarket support...
    $1500 for a low mileage 5.3 or 6.0, a $1000 cam and valve spring upgrade, and there's your 500hp.
    BB Buick- 5 grand in the short block, 3 in good heads, another 1k if you want a roller cam and not worry about oil issues... still stuck with a carb unless you drop another 3k on EFI... and then you end up with a motor that still has a weak block. Never mind the appropriate carb and distributor upgrades / rebuild, headers, aftermarket intake, new front cover, etc.
    Still, there's nothing quite like the Buick torque.
     
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  12. Sebambam

    Sebambam Well-Known Member

    Depending on what LS motor you looking for.
    6.0s are the main swap focus and therefore a bit more $$
    4.8/ 5.3 are all over the place and can be a good option I think.
    Performance wise you can wake them all up but a simple cam swap and tune.
    In terms of engine management you can go standalone harness and get a custom tune. Even mailorder.
    Or you can do a holley terminator x setup where you can do it all yourself...

    If you looking for Power and reliability nothing will beat a LS turbo build. And garage builds with up to 1000hp are more than common .

    I personally be looking for a project to put my LS combo into.
    Let's see.

    Price wise motor tranny combo
    500-2000 depending on region and availability
    Performance upgrades 500- infinity ...
    Conversion parts like mounts crossmember etc
    400-700
    Headers for a-bodies 500
    Engine management harness 400+ ecu flash etc 400 or holley terminator x 1000
    Fuel system depending on hp needs 450-800
    Radiator and cooling system parts 800
    Miscellaneous 500

    *all new part!!
     
    Last edited: Oct 31, 2019
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  13. telriv

    telriv Founders Club Member

    My son is about 1200HP with a completely stock bottom end 6.2. Original cast pistons, same rings with the end gaps opened up, Sintered iron stock con rods with stock bolts, original cam rod & main bearings, stock valves, hydraulic lifters, pocket porting ONLY on heads, his own design cam that no one wanted to grind for him, valve springs for the cam, ARP head studs. Max boost as of date 15-17pds. So far has 3 1/2 seasons on it with NO tear downs in between. IT'S ALL ABOUT THE TUNE & being conservative & KNOWING what your doing.
    Best so far in a 3200pd. car is 7.90ET@175MPH.
     
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  14. Sebambam

    Sebambam Well-Known Member

    That's amazing ..
    There are plenty of SBE LS builds out there that outperform bigblock high $ builts.
    It's really hard to not find a reason to go LS
     
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  15. telriv

    telriv Founders Club Member

    They drove it on the HotRod Drag week & logged in over 1K miles. This car is setup to drive on the street also. Has plates & insurance. On Drag Week they installed street tires between tracks a little taller & with the 3.23 gears brought the ratio down to about 2.93 & achieved just over 20MPG.
    It just blows my mind what can be accomplished with ALL the right sensors, knowing how to read everything & make changes for ALL the variables.
    The engine is out of a 2014 GMC 4wd pickup that had it's engine replaced because of loosing coolant to find out it had a cracked block which my son fixed. No reason to replace anything as the engine only had about 500 miles on it & was bought for core value of $400.00.

    Tom T.
     
  16. Sebambam

    Sebambam Well-Known Member

    Really cool.
    I have this all aluminum 5.3 boost build
    With a 4l80e that i had planned for another car.

    I guess I need a project ;)
    20191101_081716.jpg
     
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  17. sriley531

    sriley531 Excommunicado

    Here's the deal. I've long crapped on LS swaps (especially in Buicks) because they are so belly-button. But the fact of the matter is on a car with no real provenance, I get it. Big (reliable) power for little (relatively) money. It's hard to argue that. If you don't care and are going with checks and balances on the bottom line, it's gonna be hard to beat. Boring? Yeah, pretty much (IMO). But from a strictly functional standpoint, that's the bee's knees.
     
  18. Sebambam

    Sebambam Well-Known Member

    Absolutely right. You cant beat the value of it.
    Well I have my TWIN 350 build that will get EFI conversion 1st after my shop is finally built
     
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  19. Ryans-GSX

    Ryans-GSX Have fun, life is short.

    I have always liked the LS for the fact that are good reliable engines and you can get parts so easy for them if you need it fixed on the road. The junk yards have them for cheep and its so easy now to get some really strong horse power out of them. I do find I like the ones guys take time to dress out and make them look like a older engine with a carb.
     
  20. Buickone

    Buickone Founders Club Member

    When I wanted a fun "Saturday night date car" and didn't want the usual, I found this that had the all aluminum 5.3 and manual trans in it. 2002 Jaguar XK8. She liked it and I love driving it.
     

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