Stupid Question of the day: 4.3 anyone?

[63whoopie]

Ok, I believe I know the answer to this, but I was wondering if anyone has swapped one of Chevy's late model 4.3 L engines found in 1/2 trucks, S10's (?) and blazers (?) into a 60-66? If anyone read my thread from earlier this week, they will realize I'm looking to put a late-model, fuel-injected engine in my '63 to serve as a daily driver. I would only go with the 4.3 for fuel milage reasons.

Anticipated reasons people will say it's a bad idea:
1. Still have to swap all the electronics, mounts, crossmembers,etc
2. It's a V6?!!! DDUUHHHH
3. Any gain in fuel economy will be lost in the smaller engine pushing around a heavy truck (not sure of validity of statement).

Reasons it shouldn't be totally laughed out immidiently:
1. 4.3's are decent engines
2. I can get a 4.3 and a 5-speed for absolutely no money in good condition
3. They could be as cheap as a SBC swap. but with the modern fuel-injection reliability and milage (remember, we're thinking daily driver for a college student and self-employeed guy with a large gas bill already).

As much as we all like to go fast and sound loud, this could be an acceptable alternative to driving a 6-cyl late model truck with way less character and originality. I see the light in all above statements, but I have seen a few very late 4.3's floating around for chump change, and wondered if anyone had looked into this. Please chime in with comments or observations on considering this combo (but I'd still rather get a 5.3 and a 6 speed).

Thanks, y'all.

[LT1 Burb]

I had a Jimmy with a 4.3 in it and it sucked for gas mileage, less than 12 mpg. You could do better with a 350 and not have to worry about the electronics. We used to run V-6's in our ford vans at work and they changed to 8's because they get better gas mileage, and you don't have to wind em up to 5k to get them moving.

[Palf70Step]

The 4.3 would be a novelty, but as mentioned they are not fuel misers. Your MPG will be the same, maybe even a little lower with the V6. My 2002 has one and I do thing it is a great little motor, and yes it would be a decent driver, but as mentioned you might find it better and easier to go with a V8 without the electronics. I've thought several times if I find a burb or panel of doing the same thing, for the uniqueness.

If you still want to go with it, document it for those of us that have the interest in doing it also.

[TwoFiftyShifter]

I think a stock 350 or even inline 6 with the 5 speed and and 3.42 or 3.73 gears would give you just as good of mileage as the 4.3l....

[pope]

just switching to an overdrive trans will help...

[newagecustom]

I am going to start putting my 63 together soon and was considering a new inline 6 from a trailblazer instead.

[markeb01]

Conceptually the idea sounds intriguing, however back in 1995 we bought a new S10 with the 4.3 & 5 speed. Our previous car had been a DOHC 4 cylinder/5 speed Saturn that got fantastic mileage and accelerated like a bullet. By comparison the 4.3/5 speed was a complete slug, and as noted by others above mileage was lousy. It seemed like a major step backwards and I couldn’t understand why they didn’t scrap the V6 and offer the DOHC 4 cylinder Saturn engine instead. Getting an engine and transmission for free is a plus, but personally I will never own another 4.3 let alone go to the trouble of swapping one in to something else.

[rustyrodknocker]

I would not hesitate to do that swap. If you have a known good drivetrain run it. no it's not a v8 and there is no point in driving like one. its got more cubes than the thousands of 250 sixes that are in these trucks. fuel mileage is about matching a properly set up chassis with a good running engine being run down the road at the rpm that is best suited for that engine. most importantly driving it with the disipline to maximize its potentetial and being realistic about potential. I got 19 mpg out of my 292 with 4:56 ring and pinion on the interstate for a week. It was flat And I was doing 50 mph. this is not easy to stick to and probably more dangerous than doing 85. and scary when every thing on the road is blowing your doors off. but I was conducting a test. now I do 60 and get 12 at best.

[likaroc13]

yeah, i had an '88 S-10 Blazer (2wd) with the 4.3/700R4 combo...i had just sold my '93 fullsize short/step (2wd) with 350 TBI when I bought the Blazer...i was looking for a smaller vehicle that i could drive everyday & get decent gas mileage, & i would still have plenty of options for customizing...while the Blazer was a clean & sporty little SUV, it didn't get any better gas mileage than my '93 C-1500...actually, i think the V8 got slightly better mileage....that being said, i'm not sure how much the 4.3's have changed over the years as far as fuel efficiency is concerned

[LT1 Burb]

The 5 cylinder inline Colorado motor is supposed to be a great engine, lots of torque and thrifty on fuel,plus different.

[turbostar]

I think you are on to something but with a twist. I have no problem with the 4.3 v6,as that is whats in my Syclone,but then again thats not a normal 4.3. Here is what I would suggest: Chevy also made a 4.3 v8,and if I was looking for good power with outstanding gas milage,that is what I would use. Some call it a "baby" LT1 because they look the same. You could get them in 94-96 full size chevys and would produce mid to high 20's for gas milage in the original cars. They are overlooked by many swappers as they want an LT1 with 350 cu inches. If it interests you,look for a 94-96 where the 8th digit "is not P",as P signifies the LT1. FWIW

[63whoopie]

I think that the consinsus is that the 4.3, while being a different and therefore interesteing conversion, would do me no better than swaping a LS/6speed which would have a greatly increased "fun" factor and get relatively the same milage. The price increase is definately different, but the money paid in difference I guess could be chalked up to just a driver vs. a driver that can also go fast Also, the work of swapping engine/transmission/and all the dang associated electronics is just the same amount of work. The 4.3 V8 sounds cool, but I can get a whole L more displacement (for which we all know there is no replacement) and 20 something mpg with a conservative foot and rearend gear, approx to what my 2008 F150 gets.
Has no one on this board actually done this, though? I just figured that as many creative folks as are on here, there would have been someone who would have tackled this. Or some V6 swap..... maybe a turbo V6 from the 80's Buick GS's? Something out of an import (gasp!)? There are alot of V6's, esp turbo stuff if the import crowd, that go for cheap and can make some assisted power. I know Hot Rod Magazine has featured some Camaros and oddball cars with inline or V6's. Just a thought...

[Palf70Step]

I found an old link. It's with a 67, but this guy did the 4.3 into a pickup.

http://www.truckwithaheart.com/67chevy.htm

[rustyrodknocker]

you know what all those fast and economical imports have in common? they are small. almost 2 to one with a 3/4 ton pickup. as far as the ls swap that would be the same for me. If I had a known good one sitting here. I would use it. but after 150k miles on my 5.3 company truck the most impressive thing about it is that it does not leak oil. 16mpg at 65 mph. all top end power. would love to have that kind of vavle covers and oil pan on a early motor. I think it would be the perfect motor for something like an early nova, but as a pickup motor it is marginal at best.

[Clyde65]

If you needing a swap, then I would go with a 4.8/5.3 for a daily driver, mine gets 14 mostly city, I have gotten 20 on the highway, but this is with a purely stock tune, if/when I get a performance tune, it should do much better.

[markeb01]

Here's another thread with a bit more enthusiasm for the 4.3 swap:

http://67-72chevytrucks.com/vboard/s...&highlight=4.3

[blackedoutharley]

Originally Posted by newagecustom

I am going to start putting my 63 together soon and was considering a new inline 6 from a trailblazer instead.

I have said all along that this would be a great swap!

I have an '03 Envoy (same as Trailblazer) with the 4.2l I-6 and it is a great engine with good torque that would be great in a 60-66 with the right trans/gear combo.

[RollinKaos]

As most have said the 4.3 wouldnt be the conversion of choice. While it is a reliable engine and the TBI is a pretty fool proof system. You might as well go with a SBC and the TBI set up if that is the conversion style you are looking for. The V8 is actually rated better fuel economy in the full size trucks than the 6 at that time. The 4.3 was awesome in the S10 and Astro vans power to weigh wise. I am trying to talk my friend into putting a 4.3 in his Wrangler over the 2.5 he has now. I also know someone with a Samurai with a 4.3, Now that is power to weight lol.

[mikie 1954]

I don't know about everyone else but I would do it if it was me . I had a 92 gmc safary van with full convertion on it , 4 captian chairs[i think that what they called them], a couch that made into a bed[ all electric] natindo ,sink , rased roof with solar pannel, it got 19/20 mpg by itself and would pull a 2 horse trailer with 2/1200lbs horses at 55 all day long even up hill.maybe I got lucky but I realy liked that van.

[heeroyue2002]

my 02 solverado had the 4.3 and it got poor mpg.
my 94 astro has the 4.3 cpi and it can run around for quite some time!

[63whoopie]

I agree with everyone that the 4.3 is kinda redundant if someone is going to take the time, effort, and money to swap in a fuel-injected engine, but I just wanted to check with y'all. Guess I'm back to looking at the 5.3's out there.... Thanks everyone.

[clemdaddy]

your question is sound and I had the same question trying to get good mileage in a daily driver.
the direction I chose is a mild cam, low compression built 327 with vortec heads and aftermarket 2v throttle body injection and electronic ignition. T-5 and 3:55 final drive. Lighten where I can. Lower as much as springs and spindles will go and add disc brakes.
hope to get 25 mpg but we'll see.

good luck with your project and let us know how it turns out...

[GMR-PERFORMANCE]

A engine that I saw in a chvey truck that made me look twice was the dodge v-8, something like 4.7 or 4.8 dunno as the owner was note even sure as he bought it that way. But he had the complete engine& trans out of the dakota sport in his 57 chevy truck. DIfferent that was for sure.

[61_FL_Apache]

I have had an S-10 and Astro with the 4.3 I thought it was a great motor. Lots of power for a V6. Fuel milage was not too bad in my book. I think if you back it with a 5 speed, that would be a great combo.

[sailed2japan]

I've given this topic alot of thought and if it were my ride I would roll with a 292 inline 6, I think they may have only been in the big trucks. Anyway I would get it breathing throught TBI from a late 80's/ early 90's 350, since they still used a distributor. Then I would bolt a 5 speed overdrive to it and run a 3.42 axle ration or whatever worked best to keep my RPM's in the sweet spot doing 70-80 on the highway. I'd also use some moderate width tires. skinnier would be better for ultimate mpg's, but it's no use if you can't jump into traffic or corner worth a crap. That's why I think a 235 or 245 width is about right.