5 day ls swap...can it be done

[Ackattack]

I'll be embarking on putting a 4.8L engine into my 1990 K3500 ext cab over the next few days. I have a "plan" on a spreadsheet and I hope to be able to complete the project in 5 days of work (Christmas will be in there, so it won't be 5 consecutive days).



Currently the truck is has a 454 in it, TH400, transfer case (don't know which one...not part of the build), and 4.10 gears.

The 454 runs like an absolute turd. Even with the 4.10 gears I can barely spin the tires on GRAVEL. I've checked and checked the sensors and everything else and there doesn't seem to be anything wrong with the engine from a control standpoint. It just seems that the engine is shot, blowing a bunch of blue smoke out, etc, etc. Not to mention I don't really like the TBI engines.

You may be thinking that a 4.8L is kinda small for a 1 ton truck, and you're probably right, but I got is for $300 buck, so why not. We recently started a metal cutting business (www.AckermanMetalDesigns.com) and bought this truck cause it has a flatbed on it to go get sheets of steel. I may pull a trailer with it occasionally, but I'm not overly concerned with towing performance.

However, stock for stock, the 4.8L has about 30 more HP than the 454 does, though it is down on torque. However, with the 4.10 gears and no OD, I don't think it will be a problem, and the 4.8L should like the extra rpms. I'm hoping to go from 7.4mpg to something a little more respectable like 14, but we'll see.

I do have a 4L80E, but I would have to get new driveshafts and I really don't think it will be that beneficial considering that it is only a 4.8L in a relatively heavy truck.

This isn't the first engine swap I've done, so I don't expect any issues, as long as I'm not waiting on parts. I am going to make the motor mount adapter plates, exhaust flanges, and EGR blockoff plates. Not too hard when you own a CNC plasma table

[Cam-Shaft]

Curious to see your plan for getting it done. I started a motor swap with a 2 week goal... back in September. My goal is now christmas but I am thinking it will realistically get done middle of January. Oh, and make sure you add time in for the various autopart/hardware store runs you will need. Good Luck!

[MalibuSSwagon]

Hopefully you have all the parts on hand...it's a tight timetable but it could be done. Got mine done in 5 weeks, but I'm slow and there was some downtime waiting for parts.

[Tilt]

If you have ALL of the parts and info you need and and the tools, 5 days should be plenty of time.

[Ackattack]

the parts that I still need are O2 sensors, air intake, MAF, and misc stuff (oil, oil filter, coolant, etc)

I have all the "big parts" (crank spacer, new flex plate, high pressure fuel pump, ECM, fuse box) I'll just use my own HPtuner to take care of the programming

[BR3W CITY]

5 days with 2 complete trucks to start and a prior knowledge of whats involved. Otherwise, you'll run into at least one thing that turns 5 days in to 2 weeks.

[Low Elco]

Innnnteresting...... I shall have to watch!

[slotard]

Do you already have a wiring harness that will pretty much plug n play? If not it's going to be difficult.

I also seriously question 14mpg in a 1 ton with 4.10s and no OD. Not denying it'll be better than the 454 though.

I think you should be able to run the engine as if it was in front of a manual transmission.

[Aruba1]

With mine I thought 2 weekends at the most and ended up taking 2 months because the unexpected will happen and sometimes it's cheaper to order some things online and waiting for delivery instead of chasing for parts through local part stores and/or dismantlers. And life happens also, lol. Good luck though, you might be able to do it in 5 days.

What mounts will you be using?

[Ackattack]

Originally Posted by slotard

Do you already have a wiring harness that will pretty much plug n play? If not it's going to be difficult.

I also seriously question 14mpg in a 1 ton with 4.10s and no OD. Not denying it'll be better than the 454 though.

I think you should be able to run the engine as if it was in front of a manual transmission.

I found a harness that was already modified for standalone operation. I need to put some wire loom on it and build/plug in the fuse panel it came with and probably add a relay. I am planning to run electric fans, so I'll have to wire that up too.

[lowrodderchev]

I'm rooting for ya. I'm doing a LS swap in my k5 in February and hoping do get it done in a week. good luck

[slotard]

If you don't have much traffic in your area you might be able to get away with no fans for a while during winter.

[BR3W CITY]

Originally Posted by slotard

question 14mpg in a 1 ton with 4.10s and no OD. Not denying it'll be better than the 454 though.

With enough tire, and staying around 60, I think its reasonable. The higher gear will help the weight get around in the city.Depending how aggressive the tune is, I'd think 11/15 wouldn't be out of the question.

[Nodnarb76]

Good luck to you!
I'm ditching my TBI 454 and going LS also.
I pretty much have everything I need already, just waiting another week for my motor/trans from LSX4U.
I've alloted two months for mine? I figure 1 month to install 1 month dealing with the problems that are sure to arise.
To do it in 5 days sounds incredible!
As long as everything goes smooth, and you don't have interruptions stopping you, I'll bet it can be done!
Be sure to keep us posted as you go!

[ls1nova71]

Sure, it can be done no problem, provided you have everything ready in advance and don't have to keep running around to get pieces you didn't think about. You've done this before so it isn't new territory for you. Heck, they do them in just over a half hour at LSFest..... Don't forget to alot some time each evening to keep us up to date on your progress

[Cobalt964ruf]

i do them in 3-4 days in my shop. keep in mind i have done over 20 swaps as well. i wont say it cant be done but if its your first ls swap, it will be a tight deadline. happy motoring

[Ackattack]

Day 1 complete:

The first step was un-related to the swap. The fuel filler on the flat bed came straight out horizontal, so filling it was a mess. So since I had to take the bed off anyway to access the fuel pump, I went ahead and re-did the filler neck.

And while I had the bed off I changed out the fuel pump. I'm using an Airtex E3270 which I'm told is a high pressure fuel pump from a 97 chevy. It's pretty much a direct fit for the stock fuel pump. While I was in there I removed the stock rubber hose and put in high pressure fuel injection rubber hose. Not sure if the stock rubber hose would hold up to it, but oh well.

Interestingly, a TBI engine will run using the high pressure fuel pump. I had to turn the truck around and tested it out.

Then the tear down began. I pretty much got everything ready to pull the engine. I just have 2 bolts on the tranny and the engine mounts and it should be ready to yank out. I hadn't "planned" on getting the tranny bolts out and had allotted 1 hr to get the bolts out, so I guess I'm 1 hr ahead of schedule.

On another note, I'm planning on using the stock 454 y pipe and remaining exhaust system. Once I had the y-pipe unbolted, I put it up to the LS engine that was on the stand and it looked like its' very close to the same width and will hopefully fit with ease by just cutting off the flanges and welding the LS flanges that are bolted to the manifolds.

Additionally, I removed the front driveshaft. This made access to the tranny bolts quite a bit easier, but one of the other side projects I have is to replace the gasket between the tranny and transfercase, so this would have to come out at some point anyways.

[Ackattack]

Here is the 4.8L



The bed before modifications



After



new fuel pump



The 454:

[aknovaman]

I bet you a soda, that brand fuel pump will fail in the first 2 months of operation. Seen it multiple times. I recommend GM or Walbro.

[MalibuSSwagon]

I used an Airtex on my TPI swap, ran for years screaming away because unknowingly I had kinked the fuel lines, was still running when I pulled the pump for the LS swap.

[truckdude239]

Airtex fuel pumps blow i will not install them in my shop i used an ac delo ep381 on my swap mounting right in place of the tpi pump

[msgross]

good luck

[72MARIO]

I have a airtex pump in my 1990 suburban been in there for 4 years no problems. Its my plow beater truck but still rarely sees under 1/4 on a 40 gallon tank. I am not a slob running around on empty all the time either. Most likely way they fail

[Ackattack]

Originally Posted by aknovaman

I bet you a soda, that brand fuel pump will fail in the first 2 months of operation. Seen it multiple times. I recommend GM or Walbro.

Didn't know that.....guess we'll see.

Lunch time update: The 454 is out.

I did a little more measurements/work on the y-pipe. It looks like it should work, just need a little bit of 2-1/2" and 3" exhaust pipe.

Ordering some stuff from summit....we'll see if it slows me down

[aknovaman]

Installed an air tek in my old 99 burb. Lasted 67 miles. Another lasted 2 months. Buddies lasted 3 weeks in Buick regal and the list continues.

Good luck and hope you prove me wrong.