And so it begins..... 85 K5 5.3l

[79c25]

Time to repower my blazer. The 350 is still good, i just want it to be a better truck. I just got the donor truck home today. It's an 01 c1500. 5.3/4L60E 2 wheel drive. I'm still in the planning stage, trying to figure out what all I'm going to need. I'm going to be setting it up so I can pass Colorado emissions, as I'm planning on moving to Denver by next summer.

Motor mounts
Convert 2 wheel drive trans to 4 wheel drive I have a 93 4L60E that will donate to the cause
Catalytic converter
Fuel system, pump on the 01 is only a couple months old so I'm going to use that
New plugs, wires and coil packs
A/C delete
New injectors
Radiator hoses
Figure out the steam line

Anything I'm forgetting? Any help will be appreciated this will be my first swap, but I hope it won't be my last. I want this to go as smoothly as possible. Any insight to CO. emissions testing will be helpful too.

[mongocanfly]

You need to remember that on your 85 solid axle your front diff is on the pass side..on the 01 ifs its on the driver side.

[79c25]

I'm going to reuse the 85s t-case so it's all on the right side, and hopefully I won't need new drivshafts. I'd use the 93s trans withe the 01 input shaft but the 93 needs rebuilt and the 01 was rebuilt 2 years ago.

[79c25]

Well I just got to looking at the donor truck, and according to the sticker on the core support its actually a 4.8, still not to bad for the price of free. My question is, can I get a 5.3 crank and rods and turn my 4.8 into a 5.3?

[mongocanfly]

Can't beat that price..but if you want a 5.3 then I would just get one and be done with it.you could probably sell the 4.8 and recoup most of your money Around here the 4.8s get a bad rap but I have seen them push well over 400hp with only head intake and cam swap.

[Nitis]

Originally Posted by 79c25

Well I just got to looking at the donor truck, and according to the sticker on the core support its actually a 4.8, still not to bad for the price of free. My question is, can I get a 5.3 crank and rods and turn my 4.8 into a 5.3?

Pretty sure the answer is yes as the 5.3 is a stroked 4.8

[79c25]

Originally Posted by Nitis

Pretty sure the answer is yes as the 5.3 is a stroked 4.8

That's what I thought, but the gain wouldn't be worth the cost. I'll probably do cam and intake upgrades, and go from there. I don't think I need 400+ HP for a blazer that will only tow less than 4000 # rarely and see off road on occasion. I would be happy with ~350 HP and a little more torque.

[NorCalAnthony]

Nice swap! I’m gathering up parts to do the same thing to my ’89 K5 and there’s a ton of good info in this forum.

Some things that I don’t see on your list:
-VSS signal: A couple of companies make an in-line pulse generator so you can keep your stock transfer case but I’ve heard mixed reviews on them. I was lucky and found a np241c out of a 90 Suburban that is still a passenger drop but has the VSS built in.
-Fuel Pump: The fuel pump on the newer truck is usually an assembly so if you plan on using it you’ll need to get a fuel tank adapter like the one that Vette Works sells. Not sure if you can remove that pump from the assembly and switch it straight over like the EP381 pump from a late 90’s truck that most people use or not. Another possible issue with using the newer sending unit is it won’t work with your stock fuel gauge but if you’re going to aftermarket gauges that won’t matter…
-Fuel tank: You may want to look in to swapping in a tank from an 87-91 Blazer/Suburban with the baffles in it otherwise you may run in to fuel starving problems when the tank gets low and starts sloshing around.
-Radiator Hose: Most people just use the stock radiator with the upper hose from the donor vehicle.
-Steam line: Some radiators have a threaded plug below the upper radiator hose outlet that you can screw in a barbed fitting and run it from there. Another option is a coupling with a barbed nipple that you can install in the upper radiator hose. I forget who makes it but I’ll see if I can find the link when I get home.
-Transmission: It may be easier/cheaper to just find a 4x4 trans than to try and build one from the two you already have. From what I understand, it has to be taken almost completely down for the conversion which adds a lot to the cost if you’re having a shop do it. If you’re wanting to up the power level on your engine you’ll probably want to them add a shift kit and a Corvette servo while they’re at it since those trannies have a hard time keeping up with even just the stock engines. It should basically be the same size as your 700r4 and should drop right in without needing new shafts.
-4.8 vs 5.3: If you already have the 4.8 I personally wouldn’t bother trying to convert it to a 5.3, it’s not worth the time, trouble, and cost of the parts for the little power difference you’ll gain. If you do decide to go that route, you can have the 4.8 pistons put on the 5.3 rods to get you a decent compression bump. If you’re wanting to get up to 350 rwhp I’d look at picking up some used 799/243 heads, a TBSS intake, and a custom spec’d camshaft without a crazy intake and duration or you’ll shift the power band too high for a heavy 4x4 truck.
-Smog: You may want to check and see what specifically the smog laws in your area say doing an engine swap. Out here in Cali they’re pretty ridiculous and require that you swap over all of emissions items (cats, egr, o2’s, etc, the entire evap system, and the matching newer transmission supposedly because that’s how it was configured when the it was certified by the EPA or whoever... The smog ref will also hook up to the OBD II port and make sure that everything is functioning properly before they’ll sign you off. I was able to pick up a complete wrecked donor so I have everything I need but most guys out here don’t even bother with the hassle. Hopefully you don’t have to worry about any of that stuff out in Colorado though.

[79c25]

I completely forgot about the vss signal. I probably will go with aftermarket gauges, I would just need a speedometer and fuel gauge, the rest are already aftermarket. I have a while before I get to that point. I just went to look at the truck, and I think it would be best if I pulled the engine apart and replace anything that needs it. The donor has 201187 miles on it. It was a local factory truck that has possibly been abused. I agree about the transmission, but I might rebuild one of the ones that I have and just make it stronger, I just don't want it to break. But for the cost I could use one as a core and go through Monster Transmission and get a new one that will probably last longer than what I can, I'm horrible with automatic transmissions.

[79c25]

So since my wife is only giving me a budget of $2500 to do this swap, I'm going to carb the engine for now just to get it in the truck so I can put the 350 in my 79 and rebuild the BB. I will however, save up so I can go EFI in the future. For now I will reuse the carb off the 454 (since it's a new edelbrock 650 cfm) on the 4.8. That should leave me about $800 for exhaust, and I hope I don't have to have the block machined but I will find out when I tear into it.

[mongocanfly]

If you already got a complete ls I would leave it alone. If your planning on putting a carb on the ls motor a carb intake for ls motors are kinda pricey. Your gonna need the ecm anyway might as well keep the injection.

[79c25]

I plan on keeping all the injection parts, I just need to get it in the truck, the 350 is going to be taking the place of the 454 in the 79. It's not in the budget for rebuilding the transmission let alone getting a used one that works. I know in the long run it will cost more, and I found an intake with the controller for ignition for $780 on summitraceing.com

[79c25]

After much thought and research, I have decided that I will just do it right and stay with EFI. I plan on ordering a new/rebuilt transmission from Monster Transmission, since they have a layaway program. I'm also not worried about emissions for this swap until I actually do end up moving. Has anyone used the Holly EFI intake manifold in their swap, if so how is it? To cover the gauges I plan on using Dakota Digital direct replacement and their vss adapter. Anyone using a floor shifter in a 4x4 truck for an automatic? For the harness and pcm I will probably use BP unless some one knows of a better option.

[NorCalAnthony]

I would definitly do some research on Monster before you decide to go that route. They don't have a very good rep on a lot of the forums I'm on... Also, if you're still wanting to do a rebuild on your engine I would make a few calls to your local machine shops first and see what they charge. When I was looking in to having my 5.3 rebuilt most of the shops in my area were quoting me well over $2000 when you can get a rebuilt iron 5.7 or 6.0 short block from Thompson Motor Sports for the same or less. I don't have any experience with the aftermarket EFI setups but if time and money are an issue why not just stick with the stock one? They work really well and unless you're going for a nostalgic look I wouldn't bother with anything else...

[79c25]

The more I think about it, the more I want to do something different. I might be short on money and some time for now, but, time is increasing, and I plan to save a lot of money up and to start I will sell the 4.8 . I am however in the market for a couple of 12v engines, NV4500 transmissions, and NP205 transfer cases. At least looking for prices for now.

[Juiced06GTO]

You can do the swap for what you have budgeted. I did it in an 87 k10 about 5 years ago. Look up modifying the harness yourself and keep the stock efi set up. It takes time, but is fairly straight forward. I think the site I used to guide me through it was lt1swap.com. I ran my 5.3 with the stock TH400 and transfer case and used a Dakota Digital vss generator on the speedo cable. I also already had HP tuners so tuning the computer was not an issue, it is worth the money to purchase it or efi live. I was under a time crunch and was able to do it all in about a month and a half in my driveway, no garage. I ran the truck for 2 years, daily driving and plowing in the winter, before I sold it and it is still going strong!

[79c25]

The 700r4 is starting to cook it's self behind a mild 350 as it is, I don't think it will hold up very long behind a 4.8 even with a good rebuild to handle the power. I'm hanging the ls swap up and going cummins, ever since I had my first one I was addicted, it did great off road and hardly used any fuel in 16 hours of trail driving. Plus driving to and from work weighing ~6500# I was getting about 22 mpg. I know it weighs roughly 1000# with fluids but it's alot easier to install, one ground and one switched power. I know I will have to have 3/4 ton springs at least. I know more about diesel engines than gas especially efi. Also real trucks don't have sparkplugs



Just kidding. I really don't need alot of speed and if I can find a cheap 4bt I may go that route just to keep the 1/2 ton springs otherwise I'm prepared to go all the way.

[First c10]

I have a 2008 ly2 4.8-4L60e going in my sons k20. It is all stock except for the comp cams-xr259hr cam and ls1 beehive springs. This ly2 was 295 hp stock and with a torque profile cam it's should have good low end torque. I also paired it up with a np241c transfer case. My 4.8 engine has 243 heads. So your engine should run good if you decide to keep it. A 5.3 has more stroke but less compression. (I think). 5.3's have 310-320 hp 4.8's have 275-295 depending on year and RPO code.
Good luck
Scott