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Mod | | | Forums66 Topics128,026 Posts1,055,400 Members48,422 | | Most Online14,466 Apr 26th, 2026 | | AD Chevy Trucks Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
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on the Internet for over 30 years! and not clogged down with Ads! Again, thanks! | | | | Joined: Jul 2006 Posts: 451 Shop Shark | | Shop Shark Joined: Jul 2006 Posts: 451 | I own a 94' 4.3 L with 335K miles, still in van, and running good. If I did not know te miles I would swap it with no rebuild in a minute - it is that clean and has been that dependable. Can buy a 99' 4.3 L with 89K miles, intake gasket blown, and want $250 for it. Which would you go with for a swap using least amount of money? Irrelevant, rebuild required for either? Thinking I would change it over to carb, via a Holly 390 and Edelbrock intake, and swapping the dizzy out of a pre 81' 3.8 L. Would not mind a plain electronic ignition but not sure where to go for one. Would the distributor in the presently running throttl body 4.3 work with a carb/intake swap? Looking for a simple, depedable, easy, maint engine for dependable daily drivin' truck. I love the Astrovan and looking for the same power drivability in the truck. Thoughts and opinion welcome! Cavebull | | | | | Joined: Feb 2009 Posts: 35 Apprentice | | Apprentice Joined: Feb 2009 Posts: 35 | no it will not work a 3.8 and a 4.3 have different degree crank throws. also 4.3's are not all the same in 95 they started putting counterweights in them to make them run smother i have a 95 apart right now that has one. they run in the lifter gailery. it works nice but makes for a slow reving dog.
one thing i have looked at was using the 3.8 dis. housing with the 4.3 lobes and shaft to get away from the computer control of the ignition system. | | | | | Joined: Jul 2006 Posts: 451 Shop Shark | | Shop Shark Joined: Jul 2006 Posts: 451 | Bob Easist in your opinion, take my 4.3 in the van remove engine, wiring harness,sensors, computer, O2 sensor - everything. Just rebuild and install all of it in truck? I don't have a complete wiring for the 99'. So I decide to take my 4.3 TB engine out of the Van. You think, since I will rebuild anyway, might as well cam it along with the new intake and holly 390? I dont mind the TB on the 94'. Been very reliable per se'. You think cam grinds would cause the problems between the years, i.e. computer controled throttle body, true injection, and the old school carb and electronic ignition? Where would you find (year, make, model) a plain point distributor, and an electronic distributor, for a carb engine? Brett
| | | | | Joined: Mar 2009 Posts: 46 Wrench Fetcher | | Wrench Fetcher Joined: Mar 2009 Posts: 46 | you need to figure out what you want fuel inj. or tbi or carb. because fuel inj. requires a certain lobe separation on the cam grind to work efficiently. more room to play with cam grinds on carb set up. There was a early model 4.3 that was carbureted that had a standard hei distributor that would work. I think I've seen them in early model S10's I'll try to double check. | | | | | Joined: Nov 2008 Posts: 355 Shop Shark | | Shop Shark Joined: Nov 2008 Posts: 355 | lol lets also not forget a the massive wiring and computer chip required for the inj too  everything i have heard though a V-6 in an early truck shakes itself to peices
1937 1/2 ton
| | | | | Joined: Jul 2006 Posts: 451 Shop Shark | | Shop Shark Joined: Jul 2006 Posts: 451 | Cool,this helps Ragtop,
Knowing this, I went to my FLAPS Library today to do some research. Got caught with pen-n-pad (AAAAwkward!!!!).
.
I am going to rebuild the 94', 4.3L, TB. Going carb, because Edelbrock has the intake, carb, and cam options covered. I also read the 85-94 distributors are conventional HEI's. I would assume some 85's and/or 86's are standard with vacum advance from the way it reads when done quickly. The early ones have coil in cap, and later ones a remote coil next to distributor. Spark timing is controled by the Power Control Module(PCM). Finally, the 85-94 V6's can have timing adjusted, late model ECI's can not. THerfore....
The Fuel injection V6's are out. The main reason, they require an Enhanced Distributor Ignition (EDI)which houses a camshaft position sensor (provides PCM with cylinder ID)and Hall Effect Sensor (determines engine speed to PCM) sensor called Hall Effect Sensor. The owner of the 99' cannot provide all that is needed to meet these requirements.
Daniel, I understand they shake a bit because they are odd firing engines(small block Chevy's minus the front two cylinders).
Anyway that what I read. Cavebull | | | | | Joined: Mar 2009 Posts: 46 Wrench Fetcher | | Wrench Fetcher Joined: Mar 2009 Posts: 46 | the earlier 4.3 does seem to have a rougher idle. the later vortec with balance shaft has a smoother idle but you're right about the massive harness to sort through to figure out what parts you need not to mention the later ecu's control transmission shift points so yuo would throw a code unless you used the electronic overdrive trans. | | | | | Joined: Mar 2009 Posts: 46 Wrench Fetcher | | Wrench Fetcher Joined: Mar 2009 Posts: 46 | coil in cap would be the correct one. | | | | | Joined: Mar 2009 Posts: 46 Wrench Fetcher | | Wrench Fetcher Joined: Mar 2009 Posts: 46 | although they do use the later dist. in propane forklift app. I'm not quite sure how they control the advance though. havent been able to research that though,to busy repairing broke ones to try to read up on it. | | | | | Joined: Aug 2007 Posts: 1,859 Grumpy old guy playing with trucks, cars, and boats | | Grumpy old guy playing with trucks, cars, and boats Joined: Aug 2007 Posts: 1,859 | The only reason to go with the 4.3 would be a fuel injected version. I would also go for the Vortec version as it has better heads, balance shaft and 190hp. to go with a carb, etc. on a non-vortec is all the money and work of a V8, and only half the power.
Then again, it is your ride, and this is my opinion.
The problems we face today can not be addressed at the same level of intelligence we were at when we created them - Albert Einstein Or with the same level of $ - Me
| | | | | Joined: Jul 2006 Posts: 451 Shop Shark | | Shop Shark Joined: Jul 2006 Posts: 451 | "...non-vortec is all the money and work of a V8, and only half the power." good point Scott. GOt to say the wiring, computers, and numbers of sensors is a bit scary. Cavebull | | | | | Joined: Jan 2008 Posts: 239 Wrench Fetcher | | Wrench Fetcher Joined: Jan 2008 Posts: 239 | A 4.3 is certainly not the ideal V6, since it's just a 350 minus 2 cylinders. GM's best V6s are the 3.8 turbos for performance or the old 305s for grunt.
If you want to run injection, it only really requires 5 sensors. Once you get it down to that it becomes much less complicated. There's another thread about efi on a 235 that covers it all pretty thoroughly. The style of engine doesn't matter.
Devin
If you can't hose it out it ain't a truck
55 3100 63 Corvair Monza 64 El Camino 72 240Z 01 Suburban
| | | | | Joined: Jul 2006 Posts: 451 Shop Shark | | Shop Shark Joined: Jul 2006 Posts: 451 | Devin, 3.8 - were those in Camaro Z's? I have one smashed in the side around the corner... just sitting in the back of alley. I think it is a v6. Seem to remember someone bitchin' about it squeling it's tires all over town and them being suprised as it had only 6 cylinders. How can I tell if it is a turbo charged v6. The v6 will be obvious and the 3.8 will be written under the hood. Turbo charged eh? Brett | | | | | Joined: Aug 2007 Posts: 1,859 Grumpy old guy playing with trucks, cars, and boats | | Grumpy old guy playing with trucks, cars, and boats Joined: Aug 2007 Posts: 1,859 | Keep in mind, there were two 3.8 liters, the Buick derived version which started life in the early 60's and morphed into the 3800, 3800 series 2 and 3800 series 3. It also spawned the 3.0 and 3.2 V6's. The Chevrolet version was the 229 (305 with two cylinders missing) and it was a POS.
Swapping EFI engines is easy - there are many websites and manuals that step you thru. If you can wire a horn or starter and have the basics of reading a wiring diagram, your 90% there. The rest is still cut-to-shape, hammer-to-fit, paint-to-match.
The problems we face today can not be addressed at the same level of intelligence we were at when we created them - Albert Einstein Or with the same level of $ - Me
| | | | | Joined: Jul 2006 Posts: 451 Shop Shark | | Shop Shark Joined: Jul 2006 Posts: 451 | As far as TBI is concerned is my following statemement correct? "I need to make the vehicals computer (ECM) think it is running the engine in that vehicle for which it was designed. If I re-build an engine (cam,pistons, port, polish, upgrade valve train, etc.)the computer will need to be re-programed for the new specs in the motor". If so who does it and how much does it generally cost? Have been given(!) a donor vehical, motor, harness, and all - still running, but many miles. Mine to do with what I want!! I have written up specs on a motor I would like to build - cam, pistons, approx compression ratio, manuf. & part numbers, on and on but it is numbers I know will work on a carbed motor. This is my take so far from my research into TBI and TPI instalation into a bolt. If so this could be a con in my list of pro's and cons of carb versus injection - cost of re-programing to beaf up the horsepower. Also found a good artical on a TBI swap from a Chevy V6 to a JP's I6. Very descriptive and has pictures all along the way... easy process to follow and adapt to a 235 Bolts I6. http://www.bustedjeep.com/projects/junkyardtbi.aspStill liking my 235 with 2 roaches and Fentons, but I could see it going to a TBI. Cavebull | | | | | Joined: Apr 2005 Posts: 1,971 'Bolter | | 'Bolter Joined: Apr 2005 Posts: 1,971 | For all the trouble, although I think the 4.3 V6 is a great little motor, I think I'd go to a 5.3 V8. | | | | | Joined: Mar 2008 Posts: 1,775 'Bolter | | 'Bolter Joined: Mar 2008 Posts: 1,775 | The 4.3 used a balance shaft of many models starting in about 91 or 92. The balance shaft robs the motor of power and high RPMs. If you have all the electronics, why not throw in a mild small block and use your efi on it? | | | | | Joined: Jul 2006 Posts: 451 Shop Shark | | Shop Shark Joined: Jul 2006 Posts: 451 | Thanks Builder, Pretty much the consensus - v8 instead of v6 for the effort, but, wouldn't you need a 6cylinder TBI harness from a donor vehical if you were going to build a TBI 235? Kind of back to the question of computers being set for the vehical they are built for. Per your suggestion I would need a computer, wiring, sensors, etc. off a v8 to go on a v8 - take everything. A TBI computer for a v6 on a v8 would require reprograming, or a beefed up 5.3 would require its computer to be reprogramed, correct? Brett | | | | | Joined: Apr 2005 Posts: 1,971 'Bolter | | 'Bolter Joined: Apr 2005 Posts: 1,971 | Cavebull - I have thought about a V6 in an older bolt myself. I would question a "many miles" donor vehicle that probably needs an overhaul, as an expense question. The rewards are yours, so if it makes you happy then all is worth while. | | | | | Joined: Jan 2008 Posts: 239 Wrench Fetcher | | Wrench Fetcher Joined: Jan 2008 Posts: 239 | I have a complete 6.0 availble to me, out of a wrecked truck. Only thing missing is the computer. All sensors and exhaust are there. I would buy the build it yourself ecm from Megasquirt to install it. My 235 runs good though, so I've pretty much left it alone.
Devin
If you can't hose it out it ain't a truck
55 3100 63 Corvair Monza 64 El Camino 72 240Z 01 Suburban
| | | | | Joined: Jul 2005 Posts: 24 'Bolter | | 'Bolter Joined: Jul 2005 Posts: 24 | Cavebull, I put a 94 4.3 v6 in my 48 pu 1/2 ton. I got a great deal on engine back in 96, 30,000 miles on it. runs great to this day. I have a/c,700r tranny. I used all wiring and computer from donor truck it all tucked in just fine. if you would like pick i can send them to you.
Jayar | | | | | Joined: Aug 2007 Posts: 1,859 Grumpy old guy playing with trucks, cars, and boats | | Grumpy old guy playing with trucks, cars, and boats Joined: Aug 2007 Posts: 1,859 | Cavebull, the TBI motor / ECM doesnt know 4 cylinder/6 cylinder/8 cylinder if it has the correct prom. The wiring is the same, just larger injector/TB to correspond to larger engines. Swapping a V8 for a V6 in astros and S-10's is common place and no major programming required other than to tell the ignition module which engien (4, 6, or 8) and have a large enought TB/injector pair. as for EFI on 235's, there are a few TBI swaps on 235's. See Diceman's and Drummin52's conversion https://www.stovebolt.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=438357https://www.stovebolt.com/ubbthread...;Main=73318&Number=525314#Post525314As for contacting someone to re-program the ECM, contact JET performance ( http://www.jetchip.com/) or the guys at street & performance ( http://www.hotrodlane.cc/) I have used them both and had great results. You may also want to try Westers garage ( http://westers_garage.eidnet.org/) I have heard good things about them.
The problems we face today can not be addressed at the same level of intelligence we were at when we created them - Albert Einstein Or with the same level of $ - Me
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