Best late model engine for conversion?
 

Hey ladies and gents,

All the business with my radiator leak and the fact that my 350 drops about 2qts a month on the asphalt has me thinking it's time for a motor swap. My truck is my daily driver so I like the idea of a fuel injected 6 cyl with an overdrive. A late model 6 should make plenty of power, probably more than my 350... and with an OD I could maybe get 15-18mpg?

Does anyone have suggestions on a widely available, reliable GM motor that would be an easier swap? Is a fuel injected conversion SIGNIFICANTLY more expensive than a carb?

Chances are I'll end up with whatever engine I can get my hands on, through wrecks and donor and stuff, but I'd love to hear your thoughts.

Re: Best late model engine for conversion?
 

4.8L Gen 3 GM V8 and get the 4L60E to go with it (little brother to the 5.3 in the trucks/SUVs/vans. Swaps are common, parts are easy to locate and the engine/trans/harness/ECM can be had for very reasonable prices. You should be able to get 15+ pretty easily depending on your rear gears, tune, and right foot.

Any newer V6 that is RWD would work but the water is somewhat uncharted.

Re: Best late model engine for conversion?
 

Hmm, after a quick ebay search that seems to be what I'm finding. You'll have to forgive me, I'm not historically a GM guy.

So let's say I find a solid 4.3L, I'm assuming it's easier to convert it to carb than get the EFI going, right? Is either option something you think I could get done for roughly $3000?

Anything to look out for in donor motor? Certain years? What parts should I make sure are included with the engine?

Thanks!

Re: Best late model engine for conversion?
 

With a 3k Budget you could easily do a 4.8 swap (not to be confused with the 4.3, which is a V6, and while entire possible, not a swap I would spend my $$ on).

Look for a complete 4.8/4L60E pull out with harness and PCM, they will go for $800-1500 and up depending on mileage, location, what they're in... etc. There is a ton of info on the swap (there's an entire LSx swap forum on this site and countless others) and to oversimplify, it's a few ignition hot wires, grounds, and figuring out the fuel delivery/cooling/exhaust and you're rolling. The more parts you get with the take out, the better. I personally plan to buy a running vehicle for the swap, I can part the truck out and get a bit of the cost covered, plus I know it runs and drives. There are a LOT of running and driving 1999 and newer trucks and vans for $3k and under if that's the route you take.

The EFI in my opinion is the main advantage to the swap, going carb will negate most of the fuel mileage advantage and the retrofit carb set ups are pretty spendy in and of themselves. Stick with the donor vehicle's EFI if at all possible.

Re: Best late model engine for conversion?
 

Try here: http://www.lkqonline.com/custom/prod..._ENG&year=2004 they have 8 all less than 1100.00. They are a good outfit and ship to your front door.

Re: Best late model engine for conversion?
 

The more complex the swap the more down time and sorting you can expect.
If it is a matter of a worn and leaking engine it is hard to beat a crate engine with a warranty. EFI has its advantages but its not like adding a stereo. Pro rebuilt Q-jet carb on a crate motor will keep your daily driver driving. If you planned it right and did some prep you could do it in a long weekend.

Re: Best late model engine for conversion?
 

My setup is a 1995 throttle body 350, with 4L60E it is practically a bolt in set up into these trucks. Yes you will have to spend time on sorting out the factory harness or there maybe an aftermarket harness to plug and play.

I did it myself with input from some conversion books out there mainly for the electrical harness setup.

Yes it is a time consumer and there are getting to be plenty of these trucks in the salvage yard to donate the complete setup into you truck. Shop around and you might get lucky and find a good low mileage one. Yes you'll spend some money to get it right, but IMO a lot less than doing a newer style gen 3 type engine.

I'm getting easily getting 17-18MPG can pull a sizeable load in OD and go down the highway unloaded at 1600 to 1700 RPM.

Next option is a throttle body 350, with a 700R4 less wiring problems but still a very good setup.

Re: Best late model engine for conversion?
 

350 with throttle body is a nice choice........had that setup in my 94 Silverado 2wd and had lots of power and got around 18 mpg in town and it was pretty good on the highway and I was running 20" rims to. And if you go with throttle body you can do a lot of upgrades cheap and there just as easy to maintain as a stock engine.

Re: Best late model engine for conversion?
 

The 4.3 is a bad choice for a swap. It is a great motor and I would list it near the top ten all time GM motors but it is just underpowered to pull your truck around.Have you got time for a quick story? good I used to build a whole bunch of S-10's. I even was know around this region for rodding them. I had an extended cab 86 with a 4.3[ don't correct me on the year guys I built it from scratch]and a auto and 3:42 gears and a posi. That truck would get about 17 MPG and that was decent for the 4.3. I put a 5.7 TBI in there from a 89 G20 van and left everything the same as it was with the 4.3 except the headers and I had to change out the govener in the trans. I went to Street and Performance in little Rock and he burned me a chip on the way over a/c running on I-40 at 75 I got about 22 Mpg. I was happy. After the guy burned the chip yes they still did it that way then I got 26.7 on the way home on I40 @ 75 and I had bought a reclinner that was strapped to the bed. The diff was the truck weighed the same with both motors but the 5.7 worked less to do the same thing. And as far as the 4.8 goes they are everywhere!I have like 7or 8 laying out in the yard myself still in the trucks. Jim

Re: Best late model engine for conversion?
 

Yes, I would strongly recommend the 4.8 or 5.3. If you are willing to go through the work of EFI conversion you might as well go LSx.

Re: Best late model engine for conversion?
 

Hello freemonty!
I went ahead and moved this to the Engine and Drivetrain section for you. Good luck on your endeavor!

Re: Best late model engine for conversion?
 

I have the 4.8/4l60e in my 65, I get an honest 19.5 MPG on the highway and might get better on a longer trip. I also get 15+/- in the city. I have 3.73 gears and it has plenty of pep for m, not a hot rodder, just a cruiser.

I did my swap in my carport over a few months with little physical help but a ton from these guys here and also on LS1tech. I sent my harness and PCM to wait4me performance just to get the truck running and driving ( I latter changed the harness to a custom built when I had more cash), I used ECE mounts, Pierburg fuel pump, corvette type filters and a POL trans mount.

I am not a mechanic although I am not afraid to take stuff apart. I am a computer tech for a financial institution so seriously, if I can do the swap, anyone can do it!

Good luck with whatever you do!

Re: Best late model engine for conversion?
 

Just buy any TBI 4.3 S-10 2wd or Astro van or full size truck, 1987-1992ish. Stone simple swap, it's a 350 with 2 holes missing, non-electric 7000R4. 20mpg in a full size truck, all day long. Complete running vehicle is $1500, you need a fuel pump and a little wiring.
Going to carb usually costs 1-2mpg, and you get all the joys of carb tuning, etc. Late model electronic control is great.
If you want to have more go, 4.8 is nice, 5.3's are cheap and plentiful and stil get decent MPG and make lots of power, and the swap parts are readily available. 42o0 out of a traiblazer is a bit more work (trans pattern is non-standard so you need a special bell housing...) but really cool.