2003 5.3 L59 with 4L60E into 1986 C10 -- Help Please!!

[rmiller]

Hello all,

First post and obviously a newbie to the forum and the conversion game. I have a 1986 C10 with a worn out 305 backed by a 700R4. I was going to just find an old 350 and drop it in but I came across a 2003 5.3 out of a 2WD suburban that is complete with 4L60E trans, computer and wiring harness, O2 sensors, all front accessories, and pedal assy. This setup has 97,xxx documented miles.

Anyway, I have a few questions.

1. Is ~$2000.00 a reasonable price for this setup?

2. How difficult is this swap? I don't mind a little extra work but I don't want to buy the 5.3 setup and then find out I've just opened a can of worms. I know I need a fuel pump (my truck has dual tanks), motor mounts and maybe trans crossmember, but what else is involved to make this swap work? I want to keep fuel injection and AC if at all possible.

3. Are there any step by step instructions, books, etc. available anywhere that would make the swap easier?

Thanks in advance.

[Chevydillan]

I'd say 2 grand is a bit much but not a deal breaker. I bought a whole running and driving rolled tahoe for 1000 but that may not be the case where you live.
The swap really is pretty easy, a little overwhelming at first but all in all not bad.
As far as info on the swap, your in the right place. Just read read read and read some more. Take a bunch of notes and keep em all together for reference.
LT1swap.com also has tons of good info on wiring
Just set aside more money and time than you originally think it will take and take your time.

[Jmac527]

I agree 2k is a little much, I'd go 1250-1500 all day though. I've done 3 different LS C10 swaps and would like to add this bit of info....Your life will be a lot easier if you go with an '87 TBI fuel tank with '87 fuel sending unit, and just swap the pump itself with an '97 Vortec fuel pump from a truck. Use the original feed fuel line as your feed, and the vent as your return. You will not need to change the tranny crossmember, you've got plenty of other bolt holes to choose from on your frame for it. Also, just get the $40 black 1" set back swap mounts from Ebay.

This might answer your A/C question some:

http://www.ls1truck.com/forums/lsx-t...c-bracket.html

[LOWnEASY]

I second the 87+ tanks, my 95 4.8/4l80 gets starved of gas under hard launches will 1/2 or less tank due to the gas all going to the back. Full down to 1/2 is fine.
Those tanks are setup to run a TBI motor on 10-14 psi fuel pressure.
There are ways to make a bucket that goes around the pump to help and there are types of foam to go around the pump. But I would go with a cell, or sump the 87+ tank and run an external pump. Just my opinion and advice.

[Jmac527]

The reason to go with the 87 C10 tank is because it's already baffled for fuel injection internally from the factory.

[rmiller]

Thanks for all the info. I guess I will pass on the $2000 5.3 and keep looking. I found black 1" set back adapter plates on Ebay for $50. I am assuming that's what I need. Says on ad that these allow you to keep 350/400 trans or 4 speeds in its original position. I have 700R4. Would I be better off or is it easier to just swap engine only and keep my tranny or do I need to make the swap as an engine/tranny combo? Pros/Cons?

Hadn't considered the issue with the fuel tank. Definitely something I will need to look into. My truck has dual tanks on it now.

[Chevydillan]

I'd find a 4l60e if you can. The control over the trans with computer is worth it IMO

[beertestr]

Thanks for all the info. I guess I will pass on the $2000 5.3 and keep looking. I found black 1" set back adapter plates on Ebay for $50. I am assuming that's what I need. Says on ad that these allow you to keep 350/400 trans or 4 speeds in its original position. I have 700R4. Would I be better off or is it easier to just swap engine only and keep my tranny or do I need to make the swap as an engine/tranny combo? Pros/Cons?

Hadn't considered the issue with the fuel tank. Definitely something I will need to look into. My truck has dual tanks on it now.

You can do engine and trans, or just keep your 700R4, either works. You would need to adapt the TV cable to the LS throttle body but it's not the end of the world. The 60E is nicer, the PCM already can control it, and the shift points are tuneable. Keep in mind you 700R4 is used, probably worn somewhat, and even a 5.3L make a lot more power for it to handle than a carbed 305.

If you want drop in mount brackets, check mine out at KDS-performance.com, I also have them on ebay under the same username, kds-performance
With these mounts, you can run the factory mechanical fan if you want to keep the swap cost down, the stock truck manifolds work, and you can reuse the truck oilpan. Same with the accessories. Keep in mind though, that a 2WD frame will let the oilpan hang a bit below the engine crossmember, swapping to another pan like an F-body or Holley or even the H3 pan will improve clearances over the truck pan. The H3 is the cheapest, but gains you the least clearance. Something to think about if you go off road, or have the truck lowered a lot. I ran a truck pan on my 93 2WD Sierra, the pan hangs low, but it's still 8" off the ground.


Hope this helps. The wiring is not as scary as it looks, you can take most truck harnesses and rework them to be nearly completely stand alone with it's own fuses and relays. There's less than a dozen wires to mess with.