Anybody running a 4.3 in these trucks?

[Dusty4]

I'm looking for good gas mileage and dependablility. Don't know anything about these mills, other than they cost more in parts to overhaul than a V8. Any thoughts? Would a 4.3 be any more economical than a tpi 5L? Thanks upfront

[c10addict]

I am putting my 54 over a S10 chassis with a vortech 4.3... It runs strong with the S10 tin on it.. Subscribed..

[BlueJeep]

My experience with 4.3's is that they don't get very good mileage. I think a 4.8/5.3 gen III v8 would do better, with the proper rear axle gears.

But...I have a 49 chevy that I'm considering swapping on an s10 frame. If I do that I'll keep the 4.3, just because it'll be cheap (got the 95 ext. cab s10 for free).

[justplainray]

i use to own a 92 gmc safari van with a 4.3 and 700r4. that van was bulletproof. 20/21 mpg highway if you did not exceed 68 mph. bought with 55,000 miles on the clock, sold it with 245,000 on the clock. original water pump went at 168,000 miles. never had the heads off of it. changed the oil at 10,000 mile intervals, (synthetic oil) never added oil between changes. still had the orignial transmission in it. can't say enough good things about that drivetrain.
but that's just my humble opinion.
Ray

[PDW HOTRODS]

You could look for a 250 straight 6 from the late 70's. They have good torque and gas millage, and HEI. They fit very easy too.

[Atomsplitter]

I agree with BlueJeep, they don't compare with the later 1994 and newer GM drive trains. Check out the fuel enonomy numbers and power output by Googling the different motors. The difference between the 1993 5.7 TPI and the 1994 5.7 SPFI (LT1 reverse coolant flow motor from an Impala or Raodmaster) is like night and day.
1993 5.7 puts out 180hp while the 1994 5.7 puts out 260hp and gets 20% better gas mileage at the same time. There's also the L99 which is a 4.3L V8 that uses the LT1 reverse flow cooling system as well but there are very few aftermarket gooding for this motor. Both of these motors were used in Police cars and in Taxi's and they would regularly get well past 250,000 miles with regular maintenance.
Just my $.02 but these motors work best kept stock although GM performance does sell cam kits, etc for these. If you want a higher horse power mill, that you may want to soop up later, I would keep it old school with a carburator as it gets very expensive to start swapping out to bigger injectors, throttle bodies, computer programs, etc.

[Tx Firefighter]

Sure, V8s are great and mighty but people will GIVE you a 4.3.

Pistons, rods, valvetrain, front brackets and accesories interchange with 5.7 engines. In my book, that is a great thing.

[Atomsplitter]

I bought my motor for $500 and that included the transmission, wiring harness, computer, fuse block, fans, etc, etc. Basically everthing from the engine bay to do with the motor and everthing I needed to adapt the motor to my truck. All I bought for it was a new distributor, water pump, wires, K&N air filter & plugs.

[NONHOG]

My 08 Silverado is a 4.3 atm and does not get great mpg but it does get good mpg . I drive alot of stop and go and get 18 mpg average.
Yet to hit 20 on the freeway . Been close ! I am happy with it.
Sure it would be nice to have the V8 power but they were giving the 4.3 powered rigs away.

[Arad68]

I have an 02 S10 with a 4.3 and it delivers the goods. Great little engine, Lots a zip with a consistant 17/20MPG. If you get one, upgrade the Spider spritzer to the later one without the popet valve injectors. See that on the S10 Forum.

http://www.s10forum.com/forum/f107/s...de-kit-324166/

[hotrodsbyray]

Since it is a v-8 missing 2 cylinders the rebuild costs are not much different than v-8. As far as power potential check out syty.net, fullthrottlev6.com, and the s-10 forums.

[dan76]

Typically the 4.3 is a sound engine. At least one year was a carb version and that's a good one to get if you wish to stay out of FI. Performance parts specific to the motor are pricey (headers) but the engine is cheap to get since most folks are V8 minded.

[Tx Firefighter]

I like the early 90s era pickup and Astro van engines. If you decide TBI isn't for you, there are always lots of new marine engine pull off intake manifolds on Ebay that have the spreadbore carburetor pattern.

[hotrodsbyray]

another idea - get a 4.3 with a blance shaft (95 and newer) - put on a pair of the newer vortec heads with the 8 bolt intake manifolds. Get an edelbrock carb manifold for those heads, and adapter from Summit and a good 4 barrel and you can get more power and less vibration than those early years that used factory carbs - or so I have been told

[booger1949]

i have a 1949 chevy truck with a 1988 chevy astro 4.3 an love it, an u dont have to change the intake on the 88 even though it was efi, buy a plate that turns a carb to efi an flip it over, it works great, no issues what so ever, an its a peppy little motor, an very cheap on gas. if you have any ?s just email me fireater610@yahoo.com

[sixty8c10]

i put a 94 s10 chassis and drivetrian with 261,000 miles under my 47 IH (I know, not a chevy). I have been driving it now for 3 weeks with no issues, plenty of power and average 20mpg.

[tmoble]

Jeez, I have an 01 Blazer with 4WD 4dr, It barely gets 15 around town, not much better on the road. Now, I'm an engine guy and have advanced skills in this area but watching the O2 sensors output this thing is not running rich and timing looks about right.

What am I doing wrong?

[Dan Bowles]

4WD Blazer isnt a pick up. You're going to lose 2-4 mpg to carry around the 4x4 stuff. 15 is about right, tmoble.

As for the 4.3, not worth the trouble in my book. You can run an OD trans with a 350 and get comparable mileage. There are guys who can hook you up to run the TBI still and those that can tell you how to do a vortec. Unless it is free and you know what you are doing, I wouldn't (and didn't) keep a 4.3.

I am thinking about a 4 cyl 5 speed for a MPG machine, though!

[sweet70beast]

I got an 89 long box reg cab 4x4 S10 for 100 bucks so I put it under my suburban last year. A couple of months ago I got my hands on a 93 S10 blazer with 4.3 vortec 4L60e and auto transfer case for 50 bucks so I'm going to run them until I can afford the V8 swap. The blazer had an interior fire but it didn't touch the engine or trans, the firewall did it's job and kept the fire inside.