Your Thoughts On This Swap

GMCSIERRA4ME · October 17, 2009

OK, first off I want to THANK all of you for the input you gave. "Calling all dually owners"

As much as I would LOVE a dually, there were reasons for going to a 2500. (The darn fenders won't fit through the garage door LOL)

After shopping around for a 2500, I've thought of another idea.

The reason for this.......I don't really want to spend around $20K for another truck.

What are your thoughts on this?

I have a 1999 GMC Sierra with a 4.8L engine(not sure what the tranny is, it is stock).

Here are my questions:

I'm wondering if a 6L will fit right in, or will some mods be needed, ie computer upgrades etc.?

Are the trannies the same for both engines? If different, will mods be needed to fit the tranny in from the 6L?

These are the 2 major questions I have, there might be more after these get answered.

I have plans to add airbags to help carry the load.

Please keep in mind that we will only be pulling the trailer about 10 times next year and 2 of those times will be about 3 hours from home. The other times, about 1-2 hours.

HDcarpenter · October 18, 2009

I'm new to this forum, and I haven't come across any swap info like that here. if you check out ls1trucks.com they have a ton of information about putting 6.0 in half ton trucks. They are more performance based that using it for pulling or hauling loads.

As for the transmission - you more than likely have a 4l60e which is the light version. 6.0 come paired with the 4l80e in the 2500s as far as I know. I think you can put a 4l80 on a 5.3, but I don't know about the 4.8. Something else you may want to think about is your diff gears. 4.10 is the standard for the 6.0 4l80 pair.

The ecu, I'm not sure on that one. I would think it would be easier to pull the ecu from the truck you get the 6.0 out of.

Hope it helps.....

hockeypro1411 · October 18, 2009

You'll need the computer for the 6.0 and you'll need the 4l80 trans. for sure. Other things like intake and exhaust should be considered. I don't think either would bolt up directly. It may be considerably harder than you think to do this swap. When it's all said and done, you'd make out better by treating yourself to a newer used 2500HD.

Prokopchuk_9 · October 19, 2009

First off I would like too say if you stick with the 4.8 just put 4:10's in it, set of airbags and an electric fan kit and it would do fine. Your not towing very far. Second, I had. 2002 gmc Sierra single cab short box step side 4X4 sport edition, it came with a 4.8 with a 5 speed manual. I swapped in a 6 litre out of a suburban. I only took about 12 hours with me and a buddy and a case of budwieser. The 5 speed bolted right up, but I had too fab up some little motor mount mods other than that everything was pretty much the same, power steering, alternater, all that shit was the same. I did put an electric fan in tho so I don't know how much room thier would be with stock fan assembly. I had msd coil packs, wires, comp cam, comp valve train, porter polished heads, Hedman headers, bunch of goodies the list goes on. Overall the engine swap wasn't that bad I didn't think.

Keep in mind. 6.0 will burn ALOT more fuel. Like way more. But they are an excellent motor. The 4.8 is very capable tho too. Do your gears and get a black bear tune and it would do fine. And you won't stop at gas stations every 400 kms. Ahahahah

2COR517 · October 19, 2009

There's much more difference between a 1500 and 2500 than just the engine. As already mentioned, the 4L80 in the 2500 is much much stronger. Not only does a 2500 have lower gears (usually) the 14 bolt rear is significantly stronger, and 10 bolt 6 lug isn't even in the same league as a 14 bolt 8 lug full floater. 2500 has bigger brakes, springs, shocks, radiator, trans coolers, etc.

GMCSIERRA4ME · October 19, 2009

I know the 2500 is a much stronger truck all around, but like I said earlier, I really don't want to spend $20K right now.

I have a budget of about $5K and I was hoping to swap in the 6L and trans, add airbags, and a couple other minor things.

THANKS for the input so far.

Would giving it a black bear tune hurt the engine.....it has 275,000 kms on it?

Stevens03 · October 19, 2009

The 6.0 will drop right in.. and you'd need the PCM to go with it. Your 4L60e could be upgraded to handle the extra HP too by adding upgraded components. MANY have done the swap on CTW and FSC. You can find everything you need on ebay pretty easily.

It has been done

LQ4 motor

Another LQ4

LQ9 HO