Author Topic: Vortec Swap  (Read 3658 times)

Offline Hutch998

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Vortec Swap
« on: February 23, 2016, 10:58:06 am »
I've got a 94 tbi that isn't doing too hot with 260k. I'd like to pull the engine and rebuild it for my 86, however I need to know what engines I can put in my 94 first. I'd like to swap to a full vortec engine, not just take the heads and intake off and add it to mine. So how much work is involved? Do I need to swap the computer or adjust the wiring harness at all? I have a manual transmission so from what I've heard it simplifies things a little. If I do need to swap the computer, how much work is that? or am I better off to buy another tbi and call it good?
78' K10
86' K20
94' K2500

Offline CDog86

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Re: Vortec Swap
« Reply #1 on: February 23, 2016, 01:27:19 pm »
Depends if you wanna keep the injection, I have a vortec 350 in my 86 but am using an edelbrock aluminum intake to run a Holley carb so I don't have any computer on mine and I'm using a TH350 so I have no wires from that either.

Offline travisr1988

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Re: Vortec Swap
« Reply #2 on: February 23, 2016, 06:02:12 pm »
If you swap the entire vortec engine over with intake and such then you need the computer from the vortec truck. If you want to use the tbi then either get a vortec/tbi intake ($350) or a vortec/carb intake and an tbi/carb adapter ($200) and the tbi computer will work, but will benefit from a tune.
1979 Chevrolet Silverado C20 rclb cammed 355/th400/4.10 - sold
1977 Chevrolet Custom Deluxe c10 rcsb stepside 355/th350/3.42
Vortec heads lunati cam edelbrock intake headers

Offline VileZambonie

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Re: Vortec Swap
« Reply #3 on: February 23, 2016, 06:04:22 pm »
Just put the TBI adapter on a dual plane vortec intake.
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline Jr.

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Re: Vortec Swap
« Reply #4 on: February 24, 2016, 04:17:02 pm »
UNLESS you're in CA. If so you'll you'll need the cat for the vortec all the wiring and fuel injection. Otherwise those vortecs love Comp #8-414-8  670 Holley Avenger, Vortec Air Gap Summit Racing 2600 stall, 1.52 full roller rockers, headers and nice ignition. That will get you a solid 400hp/tq if not better. Factory roller lifters are fine. I've done this and similar combos with happy customers.

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Offline travisr1988

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Re: Vortec Swap
« Reply #5 on: February 26, 2016, 05:50:53 pm »
I agree with the carb intake with an adapter, much cheaper and no real loss if any. Personally I put vortec heads on the 350 from my '79 c20 so I stayed with a hydraulic flat tappet cam. I did nothing to the heads, they were remanufactured to "factory" specs, I put a lunati voodoo cam in it and it paired quite nicely. Estinated power is 330hp/440ftlbs of torque, but honestly that was with desktop dyno 2003 which is not very accurate and also favors comp cams. Now the engine I built has a 9.8:1 compression ratio and I used an edelbrock performer intake. Overall it runs great with lots of bottom end and midrange torque without a stall and with 3.42:1 rear end. If you have lower gears like 4.10:1 you can get away with a bigger cam, just be mindful of the lift as factory vortecs allow about .470 for lift if you're lucky. Over all it turned out to be a great street truck and gets going surprisingly quick. The cam jr mentioned is about as big as the vortecs would support really well, but does require a lower gear and a 2500+ stall converter and may require headwork to the vortecs. Also, with a hyraulic roller you can usually get away with more duration from what I've been told.
1979 Chevrolet Silverado C20 rclb cammed 355/th400/4.10 - sold
1977 Chevrolet Custom Deluxe c10 rcsb stepside 355/th350/3.42
Vortec heads lunati cam edelbrock intake headers

Offline Jim_Hensley

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Re: Vortec Swap
« Reply #6 on: February 27, 2016, 07:54:13 pm »
TBI loves a single plane 2brl intake.....
http://www.summitracing.com/oh/parts/edl-2912/overview/