78Blazer

Hi guys,
I am trying to figure out the cheapest way to swap engines. This is what I have come up with so far, so please slap me if I am going about this all wrong. I started 17 years ago with a stock 78 Blazer and worked from the inside out. The interior is awesome, added a pumped up 396 big block which gives me a whole 8-10mpg,(like I said 17-18 years ago..dumb) lift, 35s etc. I have so much already invested in this and it has been sitting in garage for 10 years.

My son will be turning 16 next month and I would love a cheap easy project to swap back to a small block 5.3. I have been reading many of these posts and I am a little overwhelmed. From what I have been reading is that to do this you would want to do the engine, tranny, computer, fuel system, and wiring harness. This sounds very expensive for a 78 Blazer with no AC. Is it possible to get decent power and fuel economy to just get a 5.3 at a wrecking yard here locally for $500, then get a fuel injection system from summit, and not have to worry about the tranny, computer, etc.

Thanks for any info

71403

I'd vote complete motor, trans, harness, keep factory PCM. There's plenty of swaps like yours to reference here. In the long run for most street driven swaps retaining existing trans is more work and less enjoyment down the road.

Truck swap guys can fill in the details on the xfer case issues think the drop is wrong side on the LS xfer cases.

Nick_R_23

If you want to keep it low budget, you can do what I did in my '86 and drop in a 5.3 and carb it. I reused my stock transmission. It makes things much simpler - I reused my stock harness, and there was no need for '87 fuel injected tanks and expensive fuel pumps. With a carb, you have two options for ignition, one is to use the MSD 6010 setup and use an aftermarket electric low pressure fuel pump, two is to use the GMPP distributor conversion kit which lets you keep a mechanical fuel pump and run a regular distributor.

78Blazer

Thanks... I would love to do it the "correct" way by changing the trans and the front end with the transfer case because the front drive line is on the wrong side, but because of the vehicles bone stock features I think I'd rather try to keep it simple like Mr. Nick R 23 has suggested and try to get it done as cheap as possible. What would I be losing in the horsepower/efficiency areas by using a carb with a ignition system like you have indicated? Would a aftermarket fuel injection system work? If so which fuel system would be most efficient? Thanks guys

Nick_R_23

If you know how to properly tune a carb, it can be right on par with fuel injection. You can also still get a carb conversion intake and run an aftermarket EFI system on that, such as FAST EZ-EFI. FAST also makes transmission controllers if I remember right, and that would allow you to run a 4L60E without the need to run the factory fuel injection setup. Depending on what transfer case you have and your spline count, it will bolt up to a 4L60E or 4L80E. Buying an entire aftermarket EFI kit and TCU isn't the cheap route though.

71403

Very true a properly tuned and setup carb, can match the fueling quality of a TBI system. Been there done that, had q-jets that drove and performed well as or better (mpg too) than some factory EFI systems.

Tossing a factory system with millions of $ and 10's thousands of hours in R&D, for a carb and aftermarket ign controller just doesn't ring true with me. Especially when you eval the end cost vs benefit.

Might not be a factor but if you break down away from home base there's a bazillion places to get parts and/or service for a LS motor with stock components.

To each their own. It's what this hobby is about.

78Blazer

I hear ya... I didn't even think about a TBI. If I can do a basic swap to a 5.3 with 18-20mpg without losing power for under $2,500 that would be my goal. I think I should be able to do it easily without changing the transmission, (turbo350) or transfer case and using your fuel systems that you indicated. I need to educate myself on these, and this definitely gives me a good start. If anyone else has any ideas, I would love to hear them. Thanks again for the info

Nick_R_23

Here is a general rundown of how I went ahead with mine, and should give you ideas on where to start for a budget route.

If you can get the engine for $500 or less, that's a pretty good first step. Make sure it comes with all the sensors, starter, and alternator/accessories. Those can add up pretty quick if you have to source them separate. Upper and lower radiator hoses from the donor truck are a plus as well.

For the Carb'd intake and MSD 6010 kit, talk to Mike at SK Speed. He can get you the best deal, unless you can find a used one in the classifieds. I think it ran me ~$700 for the pair shipped to my door.

Carburetors can be had pretty reasonable off of Craigslist or through friends. You can usually get a standard Edelbrock or Holley for around $100-200.

Motor mounts can vary depending on how fancy you'd like to get. You can pick up generic swap plates for ~$30 on up, or opt for DirtyDingo adjustable mounts which are $105 off their site. I ended up with the DirtyDingo mounts, and I think it was well worth it for the adjustability. It allowed me to keep my transmission in the stock location and not modify any drivelines.

The exhaust is going to be expensive or cheap depending on your current setup and whether or not you want to change it. Some people use the 5.3L truck manifolds and notch their frame, which I didn't want to do. This is a good setup if you have a single exhaust and want to use a Y-pipe. Shoenfeld makes a set of long tubes for the 88-98 trucks that fits well in the 73-87 ones, and is very reasonably priced, and would be a good choice if you are already set up with dual exhaust. 2010-13 Camaro manifolds also fit, but you will need flanges to tie in with your existing system.

A couple of other little odds and ends:

Throttle cable brackets and linkage for whichever carb you choose.
I ended up needing a Map and CKP sensor extensions due to where I placed my MSD box. ~$20 apiece
I had to rethread my temp sensor and get an adapter for the oil pressure sensor.
You will need a crank spacer to fit with the torque converter. ~$70 with bolts
I bought a 7-9 psi inline Carter fuel pump and regulator to run right in front of the splitter valve, as I have dual tanks. ~$100 for both.

That should give you a pretty good start on what to expect.

78Blazer

Great start...Thanks
Most likely the engine will come with the computer. Can you program it to work with the turbo 350 tranny? That way I wont have to change the front end and the xfer case. Or, maybe use a newer style transmission that will adapt to everything without changing the front end and transfer case? If I could do that I should be able to keep all the fuel injection the same and just get a wiring harness and do some programming to the ECM.....will that work?

Nick_R_23

That turbo 350 should be easy to hook up. You will need to run the vacuum line off the modulator into a port on the intake, and you will also need the TV cable kit to work with the throttle body. The only thing you will need to do computer-wise is have it flashed to a manual transmission if it isn't already done. I think you will need a 90-91 cluster for the speed sensor to tap into.

You could also get a 4L60E or 4L80E depending on what transfer case you have, just check the spline count and if they are the same, they'll mate up.

71403

87-91 "R/V" chassis trucks will donate electric speedo head.

It's worth repeating: getting all the pieces (engine, harness, pedal, pcm) from the same vehicle makes life much simpler and cheaper. These swaps can nickel and dime you to death trying to do it piecemeal.

https://ls1tech.com/forums/conversio...de-1500-a.html

Using a conventional trans with a DBW engine a neat trick is to hook the TV/kickdown to the pedal. There are several ways to bolt your TH350 behind a LS motor, cheapest being a stock flexplate and spacer from a 6.0 / 4l80e combo. Get the bolts with it.

78Blazer

you guys are great...Thank you so much. I will get this started at the auto wrecker with the engine and hopefully they can give me the majority of all the extra essentials I need, and maybe grab a 4l60E and transfer case that match.

78Blazer

ok.... a little overwhelmed again. What would be the best company to buy from for wiring harness, mounts etc? There are a bunch out there. I will try to find a post that gives me some options, but I was hoping someone would have some personal experiances.

Crawl

I am doing the same swap on a 78 K5. I was wondering which mounts you used? I was hoping to use the stock truck oil pan but the dirtydingo mounts suggest an f-body type pan. Does anyone know if the stock pan will clear? Also if you ran into any other snags let me know.


Thanks

LS1MCSS

iTrader: (18)

If you go carbed, you won't need a harness. It will come with the MSD box. If you go injected, get a harness from PSI. They're a board sponcer and you'll get good service from them. Hughes makes a spacer for the back end of the crank that's cheaper than the other type of flexplate spacer/bolt setup. That will allow your original convertor to work. If the motor you're looking at doesn't have all the accessories on the front, don't get it. You'll spend more money trying to piece everything together.

Crawl

I have a wiring harness, spacer, fuel pump, regulator, and everything else. I was just courious about the mounts and clearance on everything.