TBI to Carb or LS swap

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open_road_toad

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Hello everyone,

New guy here and I'm looking for some advice. I have a very nice 1988 Chevy 2wd with the stock 5.7 and 700R4 transmission (Automatic w OD and "kick down cable, no electronics). This truck was a real find for me. Bought it from the grandson of the guy who purchased it new at a local Chevy dealer. Truck had 63k miles on it when I bought it. It now has 95k. I've done a lot of maintenance related upgrades to it over the last 5 years the most recent being replacing all the front end steering components. It is my daily driver when I am not riding my motorcycle. Truck is all original with the exception of a retro tunes radio, amp and speakers.

Here is my question for you all; I need to replace the head gaskets and valve stem seals. Since I will be removing the heads I figured it would be a great opportunity to install a better camshaft. Apparently this particular engine did not come with very good heads or intake. I started down the rabbit hole of replacing/upgrading the heads, intake, convert to roller cam setup, rebuild the TBI, new fuel pump, etc. I've come to find out that there is not a lot of support for the computer that runs the TBI fuel system. So I started looking at removing that and going to a carburetor. I had a 1985 Chevy 1/2 ton 2wd that I put a Edelbrock cam, lifters, intake and carb on 15 or so years ago. That thing ran and sounded great.

Adding the cost of this stuff up it is very close to the cost of doing a LS swap. I have a buddy that has a LS in a 400 series truck and he loves it. I really like the idea of modern fuel injection and a newer motor.

What are your thoughts on the direction I should go in? I'm not looking to build a "hot rod" or anything like that. I just want a reliable truck that will run to it's full potential and sound good doing it. I would like to pull a small enclosed bike trailer in the upcoming future.

Upgrade the TBI, ditch it for carb or go LS?

Thanks in advance for the advice. My truck is the pic in my bio.

Todd
 

PlayingWithTBI

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700R4 transmission (Automatic w OD and "kick down cable, no electronics).
It's a TV (Throttle Valve) cable not a kick down. It has to be adjusted properly or you'll burn up the trans.

I've come to find out that there is not a lot of support for the computer that runs the TBI fuel system
There are ways to tune it, a lot of guys on gearhead-efi.com do/have been for years.

Here's another option I've had for a few years, with a WBO2 you can get it dialed in pretty well.

BTW - :welcome:
 

0xDEADBEEF

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From what you say want to do with it, I vote carb (or TBI as second choice) and I've LS swapped one of these trucks.
 

Schurkey

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Here is my question for you all; I need to replace the head gaskets and valve stem seals.
Scrap the crappy TBI heads. Get on the waiting list for the Summit aluminum TBI replacement heads, offering substantially-better performance.

You'll need hardened pushrods and different rocker arms, or you'll NOT use the included pushrod guideplates, and get new self-guiding/self-aligning rockers. Most folks would go with the pushrods, and perhaps higher-ratio rocker arms.

With a little luck, the coated-steel-shim headgaskets will fit the combustion chambers, making for effective quench/squish and also providing a mild boost in compression. You could ask Summit if those gaskets would work. The combustion chambers on the heads I used were too large for these gaskets, or I'd have used them.

You can keep the stock intake manifold. If you do, use the stock TBI intake gasket set having the restricted coolant hole at the rear.

You can keep the stock cam, or add a slightly-bigger cam that's still computer-friendly. My engine is using an OEM Vortec L31 cam, lifters, thrust plate, dogbones, spider, etc. The only "tuning" I had to do was to jack-up the fuel pressure a bit, and advance the timing. A custom-tune beyond that might be beneficial, but it's entirely beyond my abilities.

So I started looking at removing that and going to a carburetor. I had a 1985 Chevy 1/2 ton 2wd that I put a Edelbrock cam, lifters, intake and carb on 15 or so years ago. That thing ran and sounded great.
Good God, NO.

Adding the cost of this stuff up it is very close to the cost of doing a LS swap. I have a buddy that has a LS in a 400 series truck and he loves it. I really like the idea of modern fuel injection and a newer motor.
An entire sub-forum dedicated to the problems and benefits of LS-conversions plus carb conversions.

I'm not looking to build a "hot rod" or anything like that. I just want a reliable truck that will run to it's full potential and sound good doing it. I would like to pull a small enclosed bike trailer in the upcoming future.
If you don't want a "hot rod", there's no need for LS or for carb. A bit more power from the Summit heads, and zero driveability issues.
 

Tommy1234

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Running an LS swap in my truck. Run's pretty good. Sure it is an expensive swap for some people. The stock TBI is pretty good for puttering around town. But to be honest the LS best Bang for the buck. The thing is it's like how good are you with wiring harnesses if not I suggest isuggest like researching harnesses and computers. I run a PSI harness and it's pretty good. I run a Jeg's manifold and throttle body.
 

Tommy1234

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Another thing you may run into if you're doing the swap is fuel pumps. I used to run a walpro intank pump. Trouble is when the pump shipped the bed is finding a replacement. Luckily my buddy Joe has installed an inline bosch 044 pump.
 

studigggs

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I just want a reliable truck that will run to it's full potential and sound good doing it

Your truck in stock form is rare these days. 1988, first year of the OBS body-style, low miles, great condition, highest trim/power package...Not many of these left, and the price is only going higher. If reliability is truly your #1 priority, keep the stock computer, TBI and heads. If you want something that sounds good, throw a 'turbo' exhaust on it. If you want performance...start making changes as others more knowledgeable than me have suggested, but by doing this the reliability and maintainability will decrease. My $0.02.
 

Erik the Awful

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Reliable daily driver? I'd keep the TBI, maybe do some cleanup porting on the heads, stick with the stock cam and go with a thinner head gasket. Spend the money on a better exhaust.
 

open_road_toad

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Thanks for all the feedback guys, I really appreciate it. I was leaning towards keeping it as stock as possible bc I do think there's some value in that. That said I like the idea of getting the summit heads and doing a TBI friendly cam. I might just stay with a flat tappet cam just to keep cost down. I was planning on rebuilding the TBI so installing a adjustable pressure regulator to bump up the fuel pressure would not be a problem.

Thanks again, I'll stay active on the forum and update my progress.

Todd
 
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