8.1 into my 1500?

xXsLaYeRXx · December 27, 2019

Hey guys I been looking everywhere for a 4.8 to 8.1 swap it’s all high performance or racing related.

My 2001 Silverado 1500 with 4.8 is in amazing shape my mom bought it new in 2000 When I was 10 and gave it to me when I turned 17. This truck is my daily driver / work truck / road trip everything truck but I’m looking to give it new life under the hood. It doesn’t leak and barely uses oil I am crazy about fixing everything. a new truck is not an option I will keep this one forever.

I have 2 choices for a swap I have a choice to buy complete 2000 suburban 2500 beat 6.0 and 4l80 up or a beat up 2001 2500hd with the 8.1 and 1000 Allison.

I will have access to all the harnesses and computers to swap over with the engines after I rebuild it. With the 2500 silverado I’m thinking I can move my cab onto it after I replace all worn out items vs swapping all the drive train and suspension components if they would fit. The suburban parts do not look to be the same in the rear end and would probably have to buy 2500 parts to put in there. I tow a camper often that empty weighs 6k and is a struggle for the 4.8 to tow over 55 without it constantly shifting up and down in gears.

gas mileage is not a concern. I want to keep both engines completely stock for reliability as my current 4.8 is still stock. I’m afraid the 6.0 will still leave me wanting more power.

what do you guys think? Thanks!

Edited December 27, 2019 by xXsLaYeRXx
Adding year

Mikebtte · December 27, 2019

The daily driver situation would make me choose the 6.0

6.0 can put out a lot of power, plenty enough for many people. Have the 4.8 you will be happy with the 6.0 and 4l80 combo.

8.1 will have non existent fuel mileage and hit rod parts and maintenance is only gonna cost more.

My money is on the 6.0 with a reseal and maybe some head gaskets before dropping it in.

xXsLaYeRXx · December 27, 2019

I did have a 2003 with the 8.1 for a year or so but it was a project and not long after I got it running I sold it. It sat for about 10 years in a driveway but I remember I felt like I Could watch the fuel guage go down lol. I never got to really test is towing anything.

6.0 would probably be an easier task for me the I will also do a complete engine rebuild as well as the trans.

anyone know of a good medium performance rebuild kit that won’t reduce reliability?

i am also a heavy duty diesel mechanic and love turbos I am considering putting a turbo on the new engine any thoughts on that also?

thanks for the feedback!

CamGTP · December 27, 2019

The 6.0 and 4L80e would drop right into the 4.8 truck. You'd just have to make the transmission cross member/mount work or purchase a new one made for the swap assuming it's 2WD. 4WD may still require it but I forget.

If your current truck is 4X4, that is another task for figuring out the transfer case and drive shaft lengths.

If future plans are a turbo or something you will need even more parts. Like better connecting rods, better pistons so you don't need to worry about them. The rest is fine, the block and stock cylinder heads take boost just fine. There isn't much to rebuild depending on what you are going to do. Clean it, quick hone job, gap the piston rings for NA or for future boost, new head gaskets and all that jazz. Consider the trunnion upgrade for the rockers, it's good peace of mind stuff.

Other little odds and ends like bigger fuel pump, larger injectors, 2 or 3 bar map sensor for boost, spark plugs etc etc will be needed. You'll want larger injectors too if you mod the engine and don't go turbo yet, the stock ones aren't very big and max out even with minor bolt on's.

As you can see it's a giant worm hole you are opening up with mods. There are endless possibilities here.