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TPI and Vortech Heads - not compatible - suggestions needed

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by BurbinOR, May 16, 2000.

  1. BurbinOR

    BurbinOR 3/4 ton status

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    Well, seems after confirming with two sources (one being Jim Pace Performance Parts) Vortech heads are NOT compatible with my TPI. In fact, there are very few heads available for this combination. My story - have a rod knock in my 406, needs attention. No problem, but if I want to upgrade my heads (currently running the '87 IROC heads that the TPI came from) or go with a crate motor, ALL the heads they put with the motors are meant for the dreaded carburetor. One option is to drill out the heads, I am being told the ports don't match up properly then, or try an Edelbrock base plate for the TPI to sit on, which the guys weren't sure would be a perfect match either.

    Guys, any ideas or suggestions? Seems I have the following options -
    1. Stick with the TPI and heads I have, freshen them up when I repair/rebuild the bottom end.
    2. Go with Vortech heads and go back to carburetion (not what I ever wanted to do).
    3. Try to make the Edelbrock base plate work with the TPI on Vortech heads.
    4. Sell the TPI system and heads to a lucky K5 owner and go back to carb and HEI.

    Thanks in advance for your wisdom.

    '79 - 406 w/IROC TPI - K5#5 - a <font color=orange>sickness[​IMG] <font color=blue>you never get enough of!! [​IMG]
     
  2. Blazer1970

    Blazer1970 1/2 ton status

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    If Edelbrock makes a TPI base that has the factory Vortec intake bolt pattern, that would be ideal. The Edelbrock TPI bases are supposed to be a big improvement over the factory ones, particularly if you started with a 305 TPI system. Otherwise, I think I would look for some other reasonably priced aftermarket heads that will work with your TPI system.

    Tim

    1970 Blazer CST 4X4 350 SM465 NP205
    1987 Suburban 4X4 350
    1988 Chevy Pickup 4X4 350
     
  3. Shawn

    Shawn 1/2 ton status Premium Member Author

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    Are you saying Dart or World Castings won't work with the TPI? If thats the case, I'd just stick with your current heads and drop some bigger valves in them and port/polish them. You may want to talk to a cylinder head shop. They might be able to match everything up.

    Shawn
    87 K5
     
  4. Blazer79

    Blazer79 1/2 ton status

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    My brother has TPI in his 86 Camaro. He's done some research on this. He found out that it IS possible to modify the Vortec heads to get the ports of your current base plate aligned. He suggests you visit http://www.camaroz28.com and http://www.thirdgen.org. These Camaro guys know a lot about TPIs.

    Now if your TPI is giving you lots of trouble (like his) and you keep spending money on fixing (like he is), I'd say sell all that TPI stuff and get the Vortecs, and Edelbrock intake & Q-jet. It won't let you stranded. All you need to fix it is a screwdriver, and cost of repairs are 1/1000 of his TPI repairs. He's jealous of how easy my Blazer starts in cold mornings too. He's sick of all the TPI trouble.

    <font color=black>//////
    What the heck!...Drive it like gas is $0.50/gal!!!
    </font color=black>[​IMG]
     
  5. blazer72

    blazer72 1/2 ton status

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    yea but the carbs wont run dam near upside down like the TPI will, nor do carbs have near the tork of a TPI at low rpms
     
  6. Tommy

    Tommy 1/2 ton status

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    I have fooled with a few TPI's in the past. I would go with a set of darts, me and a buddy had good luck out of them. The stock tpi base is the same wether it was a 305 or 350, only dif was the injectors and chip. I had the stock heads do a great job also, just wanted more for racing so I went Dart. Just my .02 cents
     
  7. Jamie

    Jamie Registered Member

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    Ive heard that GM is comming out with a TPI base manifold for the vortec heads in Oct. I seen the info on this site SDPC2000.com I run these heads on my 400 and would rather have a TPI setup than my Q-Jet.
     
  8. Nrose07

    Nrose07 1/2 ton status

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    First question is why do you want Vortec heads? You can get a set of these that are drilled for old style bolt pattern, but you would loose some intake flow since the ports won't line up. But the combustion chambers are what make the power with these heads anyways. Any set of non-Vortec heads would be good as long as they have the flow you want. The TPI is a piece of SH*# ,uhh my phone number is 453583405, I'll just take off your hands for you. KEEP IT!!! I have a TBI, and all I want for Christmas is a TPI. Don't think about using a Edelbrock base, would never work. Get a good set of aluminum heads or get a set of Corvette heads for the TPI. Hope it helps! Matt

    Displacement, cubes, and did you say you drive a riceburner???
     
  9. BurbinOR

    BurbinOR 3/4 ton status

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    Shawn, the cost I was told for other "compatible" heads was like $1500 a set, the Vortech's of course are almost $1000 lower. Nrose, pretty much want a "new" set, had problems in the past with "rebuilt" heads, cracking, etc.
    Gotta agree with ya, I want to keep the TPI, wayyyy better low end compared to my Q-Jet and Performer combo. Plus where I travel in Oregon I am going over 4,000 foot elevation passes, and the injection makes a big difference. Hope that Chevy part number for the conversion from TPI to Vortech happens soon........

    '79 - 406 w/IROC TPI - K5#5 - a <font color=orange>sickness[​IMG] <font color=blue>you never get enough of!! [​IMG]
     
  10. Tommy

    Tommy 1/2 ton status

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    I agree with nrose, forgot about the vette heads, but those flow pretty good. you can buy them new, but can usually find a good set for $400-500, ready to bolt on.
     
  11. KapeKodK5

    KapeKodK5 Registered Member

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    The only way to go is a set of L98 factory corvette heads. Perfect small port compression heads and the Tpi bolts up perfect. A little pocket porting and you can easily get 350 to 400 horse with the right cam and some hi po parts. I have done quite a bit of research for me tpi motor. Your other alternative is AFR heads Big$$$$$
     
  12. BurbinOR

    BurbinOR 3/4 ton status

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    Sounds like the L98 heads won't be cheap, either. Any ideas on locating some? Boneyard stuff maybe.........doubtful they would be laying around. Good idea though, now to find some.....

    '79 - 406 w/IROC TPI - K5#5 - a <font color=orange>sickness[​IMG] <font color=blue>you never get enough of!! [​IMG]
     
  13. Truckfan2

    Truckfan2 1/2 ton status

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    go to http://www.copart.com/ and look up the cars that the L98's came in (Corvette, Camaro). From there, get the yard # and call them up to see what they can do for you. I know there are some yards that specialize in Corvettes and Camaros.

    NEVER been stuck... *yet* (4wheeling)

    Stuck for 10 months (At school)
     
  14. dumbfounded

    dumbfounded 1/2 ton status

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    Well it seems I add more than ask questions but this is something I know something about. I've got a 400+ hp 86 vette with the TPI. If I were you I'd dump the TPI unless you have done major modifications to it. TPI is great for the 5.0 and 5.7, if you are running a 406 (I was going to go with a 420 in the vette but the expense involved with the TPI alone was incredible) See the TPI is like any other injection system it was made for a particular size 5.0 or 5.7. Motor size can be Increased but the runners, base plate, throttle body on your set up are hurting you if they are stock. Also a new chip needs to be burnt to your specs. Again this is expensive with lots of down time (its trial and error and you'll fight with the mail waiting and waiting) Accels DFI system can cure the programming part and you tune with a laptop (lovely) but $800+ is alot of $$$$. And we can't forget about different injectors a 406 would need about 24lb. If memory serves me the irocs were 19 and the vette was 21 or 22 thats more money. my L98 heads on the flow bench were the worst flowing heads I've ever seen for along time. And there is not much meat for extra room. Ported trick flows or air flow reaserch heads is what my buddies use. Again the expence Starts at about 900 for tfs and 1200 for afr heads. Keep in mind I've had years of experience and I went with a bulletproof lightend 355 that revs up in a split second I feel less rotating mass is alot better than alot of cubes again this is for racing. All in all for TPI go with all the goodies or back to a 350. I know the TPI looks great polished under the hood of a k5 but it's not a good set up unless you have $$$$. Well this is getting long any other questions just ask, but I'll probably think of something in my sleep so I'll be back!!!!!!

    Blood, sweat, tears, and lots of money is what keeps the k5 alive.
     
  15. mpikas

    mpikas Registered Member

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    The TPI will have kickass low end, compared to just about anything else (the only thing that I know of that has better low/midrange is the early 80’s crossfire setup). Anyway, car guys don’t like it when it comes to making things go fast, since when you start modifying it you run into 2 problems: Too much low end (cars are light, decent gearing, no matter what compared to us tiny tires diameter makes a big difference) so they can’t hook. The second problem is that it doesn’t breath up high. Unless you’ve significantly lightened your truck and run smaller then stock tires, these shouldn’t be a problem for you, but instead, advantages.

    Depending on how much money you’ve got to spend, I’d look into a few different things. Porting the stock heads is a waste of time, they are light weigh castings that don’t have the meat to be really modified to something substantial. Ported vette aluminum heads, they’ll have smaller, high velocity ports which will help build more torque, plus the aluminum will allow you to run higher compression with higher loads and more timing for better gas mileage and more responsiveness. Even unported these will be better then your stock heads (btw, if you find the very rare f-body with an L98 motor, this will not help, since they had iron heads anyway, but they are different then the more common TPI 5.7). Next up would be some of the world products heads and similar products, and finally something like the AFR (Air Flow Research) heads, which ported will really rock. With some of the better heads you’ll probably want to look into larger bases and runners, or siamesed runners. You’ll want to keep to heads with smaller ports but higher velocity, the opposite of what the bigger race style heads have, but your motor will tolerate larger ports then a 350 would. Another consideration is that where most people will tell you that you won’t gain much with much larger valves, that’s because most tests are done with the heads on a 350 bore. You’ve got a larger bore which unshrouds the valves and you’ll probably gain with larger valves then a reasonable budget will allow (read: get the big ones).

    Ask around from the actual manufacturers. The vendors might not know all their options, most can setup their heads to work with a tpi (ex: AFR makes their 190cc heads in standard sbc, tpi, lt1, lt4 and other models)
     
  16. Blazer79

    Blazer79 1/2 ton status

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    Now that's a very nice and informative post. I wish they were all like this. Congrats mpikas![​IMG]

    <font color=black>//////
    What the heck!...Drive it like gas is $0.50/gal!!!
    </font color=black>[​IMG]
     
  17. dumbfounded

    dumbfounded 1/2 ton status

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    Well I did think of a few things. It sounds like money is in some what short supply so you are looking for low dollar hp/torque. I'll have to agree TPI has good bottom end due to the long runners. I'm not sure if you have speed density or mass air. My guess is speed density unless you fabricated an airbox to accomidate the mass air sensor. If its speed density you may not have too much trouble b/c your displacement is only like 26% more. But anything which would change manifold pressure would hurt more than help. It may be those crappy heads keeping you in check. Anyways I'm not going to get on a tangent again. If money is tight for new heads I would substitute. Buy a dremel tool with a few strong bits and hog out your plenum and take a little meat off the runners and base plate. As long as you don't go nuts you can't really hurt them. port match the heads and manifold. If you have a die grinder you can get a little meat off the heads if you are careful. The reason I say this is a 350 will run with a carb off of a civic but it will run like crap. I'm afraid if you do go with the vortec and spend some dough the outcome may not be as good as you hope. I'd take the meat out, get a chip, and a kick a$$ exhaust with some good headers. I hate for people to spend alot of dough with high expectations and get dissapointed. Trust me I've listened to ad claims bought products done extra tricks and the only one who liked it was MR.VISA. This way you can keep the TPI get alot more umph and have extra cash to spend on a lawyer for tickets.....

    Blood, sweat, tears, and lots of money is what keeps the k5 alive.
     
  18. BurbinOR

    BurbinOR 3/4 ton status

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    You guys are awesome. Man, what a wealth of info........now, to figure out exactly what to do. Seems that L98 head idea might be a good one to pursue. Kinda stuck on keeping the TPI as I could not believe the drivability, torque/seat of the pants feel improvement it made after changing it for my old Q-Jet and Performer manifold. AND the carb was performance built, ran perfect.........so I gotta say the TPI is worth the effort. Thanks again......let y'all know what I end up doing.

    '79 - 406 w/IROC TPI - K5#5 - a <font color=orange>sickness[​IMG] <font color=blue>you never get enough of!! [​IMG]
     

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