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400ci Swap

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by MudFrog, Mar 20, 2001.

  1. MudFrog

    MudFrog 1/2 ton status

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    Hey everyone..
    A buddy of mine has a 79 K5 blazer. It currently has a 350ci with TH350 and NP203. He was driving it the other day and the engine locked up on him, and the tranny is going too. We have looked around and we are trying to get him back up and going better than ever for around $2000.

    The local Autozone has 350 and 400 long blocks for 1299. We are leaning towards the 400. What else will we need to do to complete the swap? We are looking at the performer intake manifold. Holley 750 silver series and headers (not sure which brand). Other then the obvious, water pump, spark plugs, distributor. What else will we need to replace? Also will the 400 bolt up to a TH350 or TH400? How much HP does a new 400 put out (rough estimate).

    Do any of you have any better suggestions? Or do any of you have any 400 or 350 engines for sale?
    Thanks for the help!

    89 K5 Silverado
    <A target="_blank" HREF=http://mudfrog.coloradok5.com>http://mudfrog.coloradok5.com</A>
     
  2. 78Blazer

    78Blazer 1/2 ton status

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    1299?? I bought a 400 long block from them roughly 2 1/2 yrs ago and I only paid I believe 699.00 for it.

    Scott
    78blazer
     
  3. CaptCrunch

    CaptCrunch 1/2 ton status

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    Hard to say w/out engine stats... compression? what heads, etc. 400's were offered in many late 70's truck so is pretty much a straight swap. One downside is the 400 has been known to have problems with head gaskets and overheating... although it is not a huge concern. IMO I'd either buy a short block of one and throw on vortech cylinder heads or else looking to a 383 stroker motor... lots of torque and power. Just my .02. In all reality the 400's are probably just stock rebuild from the late seventies... not much of a step up really. Everything should bolt up, but the tranny change could affect what adapter you need on the T-case and the drive shaft lengths. Good luck

    [​IMG]
    1987 Chevy K5 Blazer- 350 TBI
     
  4. MudFrog

    MudFrog 1/2 ton status

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    I haven't seen what comes with the 1299 version myself, but he said it has everything, including a 2 year warranty, a dyno sheet and it has been broken in. What came with you LongBlock for 699? Everything but manifold and carb and that kind of stuff?

    89 K5 Silverado
    <A target="_blank" HREF=http://mudfrog.coloradok5.com>http://mudfrog.coloradok5.com</A>
     
  5. 78Blazer

    78Blazer 1/2 ton status

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    I had to swap my intake, carb and all the sheet metal stuff on the motor to it (oil pan etc.) It may have been 799 but I am pretty sure it was 699 cuz my grandpa also bought a 350 from them shortly after I got mine. I also just installed another one of there motors in my dads 89 chevy about 15,000 miles ago and have had no problems.

    Scott
    78blazer
     
  6. MudFrog

    MudFrog 1/2 ton status

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    If thats the case, I need to see what comes with the 1299 version. Because if the difference is $500 for the covers and pan. Lets do the math. Thanks for the help 78 Blazer. I may hit you up for some more questions.

    Anyone else have ideas about what he should do?

    89 K5 Silverado
    <A target="_blank" HREF=http://mudfrog.coloradok5.com>http://mudfrog.coloradok5.com</A>
     
  7. MudFrog

    MudFrog 1/2 ton status

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    CaptCrunch,
    You think he'd be better off to stay with the 350 then? They are the same amount of money, and I know parts are cheaper for the 350. We are looking at the long run, of what we can do to build them up. Which is easier to get HP and torque out of? He'd like to go with the 383 but that is some money to invest into getting one of these.

    89 K5 Silverado
    <A target="_blank" HREF=http://mudfrog.coloradok5.com>http://mudfrog.coloradok5.com</A>
     
  8. MudFrog

    MudFrog 1/2 ton status

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    78Blazer,
    I just went to autozone and talked to them myself. They have 2 versions. One is a long block with all new parts for 1299. The other is a long block with remanufactured parts for 799.
    Those are the 350's.
    The 400 is 849 with a 1 year warranty and remanufactured parts.

    89 K5 Silverado
    <A target="_blank" HREF=http://mudfrog.coloradok5.com>http://mudfrog.coloradok5.com</A>
     
  9. HarryH3

    HarryH3 1 ton status Author

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    You can get the new 350 long block right from your GM dealer for around $1,299 as well. For a few hundred dollars more you can get one that puts out quite a bit more power. Check out <A target="_blank" HREF=http://www.sdpc2000.com>http://www.sdpc2000.com</A> for more info on what's available straight from GM.

    <font color=black>HarryH3 - '75 K5</font color=black>
    <A target="_blank" HREF=http://ThunderTruck.ColoradoK5.com>http://ThunderTruck.ColoradoK5.com</A>
     
  10. 78Blazer

    78Blazer 1/2 ton status

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    I got the remanufactured one. But it was the same as the 350 when I bought mine I know that cuz my grandpa picked up a 350 shortly after. At that time I think the reman was all they offered. The more I think about it to I believe it was 699. I paid but like I said it was 2 1/2 yrs ago. Im gonna go see if I can find my reciept to it.


    Scott
    78blazer
     
  11. CaptCrunch

    CaptCrunch 1/2 ton status

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    It's really a toss up... 400 has 50 extra cubes... although with the autozone motors I think the heads will be your weak link. I know nationwide engines sells a 4 bolt short block for about $650... could grab some vortech heads for 400 and that would be a lot better then the 400. Overall the 400 would be a little better then the 350 from autozone. Probably nothing real substancial... If it is me... I want my truck to keep up w/ the newer trucks when I hit the gas if I'm shelling out 1200 or 1500. Just my opinion... if you are looking for ease... then you can get a stock GM crate motor for approx 1300 and then you don't need to add a came or anything.... just drop in the motor... I'd really try looking into a short block and throw on the vortech heads... they make a ton of power and are as cheap as just about and head out there.

    [​IMG]
    1987 Chevy K5 Blazer- 350 TBI
     
  12. Wingnutt

    Wingnutt 1/2 ton status

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    Hey Mudfrog,
    Long time no "see".
    Anyway the only drawback that I know of; if it is really a drawback, is that you have to follow the warrenty instructions TO THE LETTER! for the Gen II engines, that means changing the oil and filter at EXACTLY every 3k miles. Oh did I mention that they force you to use Mobile 1 oil and filter for every change....for 2 years? Not exactly a drawback, just kinda expensive. I worked for them part-time while I was going to school and IMHO these are very good engines (for the price), but the heads are the weak link. They don't go over them as thourghly as they do for the rest of the engine. These engines come with a dyno sheet and usally make 30-50 more HP than a stock engine. The warrenty is for two years, unlimited milage (best to check that though, it's been 2 years since I worked for them). All that aside, personally I would go with HarryH3's suggestion and get a GM engine; simple because each AutoZone store manager is under strict orders to do anything to prevent a return or exchange on thier engines. And believe me, when the times that I saw problems with these engines, the store manager was VERY reluctant to help. Did I mention that they loose any bonuses for the quartar if they provide an exchange or refund for thier engines? IMHO I would save up for awhile if I were able and get a GM 383 stroker. Ooops almost forgot, the 400's were externally balanced (if memory serves correctly) so you will need a 400 damper and flywheel/flexplate if you go that route.

    Also BTW, stopped by 4X4 extreme, and the guy that runs the place seems to have had an attitude adjustment. He seems to have lost his know it all attitude and listening to him talk to some kids about lifts, he is now trying to get people to do things right instead of just selling parts to make a quick $$.

    P.S.
    Drop me a note sometime, we need to get together and explore some trails, I need to find some new ones.
     
  13. MudFrog

    MudFrog 1/2 ton status

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    Wingnut,
    How the heck are ya man? I think he might be leaning to the GM 350 crate engine for 1300. But I'll run the idea of the shortblock and see what he thinks. Neither of us has ever done the engine swap so this will be an experience. Let me give you my # and you should give me a call sometime when you come in to Roanoke. I'm glad to hear the 4x4 Extreme guy is changing around, maybe I'll actually go back now. Have you been up to Crowel Gap? If not you gotta hit it with me. It's sweet.

    CaptCrunch,
    Thanks for the heads up, I'll deffinetely show him your post and see what he thinks about the vortec heads. I know he wants to get as much Torque and HP as he can for the buck.

    89 K5 Silverado
    <A target="_blank" HREF=http://mudfrog.coloradok5.com>http://mudfrog.coloradok5.com</A>
     

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