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TPI swap question

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by MA87K5, Jun 17, 2000.

  1. MA87K5

    MA87K5 1/2 ton status

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    I would like to know if putting a TPI unit on a 383 stroker would be worth the hasle and if I would need a fuel pump to go with the TPI? It will go in an 87 K5 that has a TBI 350, 700r4, np208, 3.42 rear, and 33 tires. Thanks for any input. The 383 has already been running with a edelbrock carb and intake, and has aroung 10k miles on it.
     
  2. Tommy

    Tommy 1/2 ton status

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    You will need a high pressure pump to supply fuel.
     
  3. MA87K5

    MA87K5 1/2 ton status

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    Thanks Tommy. I was afraid of that. Apparently no one else can tell me if the swap would be worth it. This is the second post that I have put here concerning the TPI. The last one nobody answered. I'm beginning to think nobody knows about TPIs. Does anybody know?
     
  4. jmpd

    jmpd 1/2 ton status

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    I swapped an 88 Camaro complete motor back in 1990 into my 84. Back then not a lot of info was out regarding the swap. It turned out nice. I used the in-tank fuel pump out of the Camaro, I used the wiring harness and made the right connections for the TPI system to work. Any questions. I will be happy to answer. I in the middle of rebuilding the motor and porting and polishing the TPI

    Michael
     
  5. Tommy

    Tommy 1/2 ton status

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    I think it would be a very worthy swap. The tpi makes gobs of torque, especially when put on a 383; this is my plans, hopefully for the near future. Suncoast conversions makes a very informative book on the tpi swap. I have swapped a tpi and a LT1 in my 69 Z, I think I'm gonna go with the TPI for my 70 K5.
     
  6. Blazer79

    Blazer79 1/2 ton status

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    I read what I can about the TPI swap because I want to do it to my Blazer too. I also want to stroke my 350 to a 383. I think TPI is one of the best upgrades you can do to a Blazer, since one of the TPI's benefits is its low-end torque, which we need a lot to move our heavy beasts.

    From what I've read, you must take EVERYTHING from the donor vehicle. Do not cut or splice the harness. You must know exactly from what kind of engine the TPI came from (VINs) so you can buy parts for it later. If you remove it from a 305 and install it in a 350, you must change the injectors to larger ones. I don't know if the 350 injectors will work in a 383, though. You definitely need a different fuel pump because carbs need about 7psi to work, while TPI needs around 30psi. Another issue you may find is that you'll need to take the cylinder heads from the donor vehicle, since the TPI manifold will bolt only to TPI style heads. If you have headers, you'll need to install an O2 sensor on them (or at the collector) for the TPI.

    This is all that I know (yet). I know I could be mistaken on anything I said here, so please correct me if I'm wrong.

    <font color=blue>//////
    http://blazer79.coloradok5.com
    </font color=blue>[​IMG]
     
  7. Tommy

    Tommy 1/2 ton status

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    The tpi can bolt to just about any heads, you may have to elongate the center holes, but it will bolt up. As for injectors, I would put in a set of 350 injectors for a 350, even a 383. I look at it this way, I would probably run a 600 Edelbrock, maybe a 750 on my 383, a stock tunedport will flow in the upper 600 cfms, so unless you wanted to swap, a set of stock 350injectors should be okay. As for the headers, just weld a bung from K&N,(10bucks) into your existing headers.
     
  8. MA87K5

    MA87K5 1/2 ton status

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    Thanks everyone for your help, I greatly appreciate it. I also found that 85 and 86 TPI will fit on 86 and earlier V8s. Without any mods. How much do 350 injectors go for?
     
  9. BurbinOR

    BurbinOR 3/4 ton status

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    By the way, there are a few of us TPI guys on here, mine was swapped off an 87 IROC to my 79 K5 with a 406 small block. The injectors "seem" fine as far as enough flow for my extra 56 cubic inches of motor versus the 350 it used to supply. It is WELL worth the swap. Fantastic low end, drivability much better than any Q-Jet (and I happen to like Q-Jets!).

    <font color=black>'79 K5 - 406 w/IROC TPI -<font color=orange> K5#5 - <font color=blue>http:// www.blazzinor.coloradok5.com
     
  10. HarryH3

    HarryH3 1 ton status Author

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    The stock 305 injectors flow less fuel than the 350 injectors. I don't recall the exact numbers, but since my 350 injectors were defective (and GM wouldn't warranty them since the engine was no longer in the Corvette they had put it in), I went ahead and bought injectors that flow about 2 lbs/hr more than the stockers. This works great on my 383, even with a bit too much cam for an off-roader. [​IMG]

    Plan on spending $400-500 on a set of injectors. They aren't cheap. [​IMG] Certainly makes it worth your while to search out a TPI from a 350 in the first place. [​IMG]

    <font color=black>HarryH3 - '75 K5</font color=black>
    http://ThunderTruck.ColoradoK5.com
     
  11. TPI86

    TPI86 1/2 ton status

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    A TPI system would work great. I am presently runninga 85-87 TPI on my 1986 K5. I presently have two TPI systems for sale. Both will fit the older style heads without any mods. Yes you will need a high flow fuel pump, they cost anywhere from $100-180. I am using 305 injectors on my 350 and it runs great. I am usinga 1990-92 computer w/speed density system. Speed density is cheaper to run, but dont now much about performace difference from maf set up. I fyou have any questions reply, or need more info. Painless makes a great harness that plugs right into all the sensors.
    Eric B TPI86
     
  12. dumbfounded

    dumbfounded 1/2 ton status

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    Go and buy a mustang magazine (I know, I know) I've used mustang injectors a couple of times in my vette. They have the same plugs, but you have to get the correct ohm rating. Off the top of my head I can't remember. They are about 70% cheaper and you can get them in all kinds of sizes. This is something most don't know, but it's alot better than the high price of chevy injectors.

    Wasn't me.............
     
  13. MA87K5

    MA87K5 1/2 ton status

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    Thanks for the mustang injector info. What year mustang though? I am learning alot from everyone thank you very much.
     

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