CoreyH

Hi everyone. Have been doing alot of research and maybe im not wording my searches right, but I am interested in converting my 04 Trailblazer with the I6 over to a 5.3 LS motor. A buddy has a 5.3 block he will sell me, and some other people have given me some ideas on parts, but what all would really have to go into this type of conversion? I know the PCM will need to be replaced, motor mounts, and I've head my 4L60E transmission will bolt right up. Is there anything else? Just want to know everything up front before I go spending money on this build and nkt being able to make it work.
Thanks!

operatorfailure

iTrader: (3)

TBSS or v8 TB motor mounts and oil pan. If it's 2wd get the bat wing corvette oil pan to avoid the front sump disaster that the TBSS pan is. Either TBSS headers or stock TBSS manifolds. Not sure on DBW pedals, but I'm guessing the one in your TB will be able to work with a similar year 5.3 throttle body. Good luck!

CoreyH

Will TBSS headers work since its for a 6.0 and this being a 5.3?
As far as throttlebody goes, I'll be looking into most parts that fit a TB EXT, so that shouldn't be a problem.
I do want to keep my AWD, so I know I have to get an oil pan from a EXT, just not sure what all will work from a 6.0 to a 5.3.
This motor im getting is complete, minus the heads, was thinking 243 heads, sending those to the machine shop for some work. If I run a turbo cam in it without having a turbo, will there be any issues with that? Or should I just run something else until im ready for a turbo?

superdave84

All of the LS and truck blocks are identical as far as external measurements, etc. 4.8, 5.3, 5.7, 6.0, 6.2....all the same on the outside. All oil pans bolt up, and headers will bolt to all the heads. They SHOULD fit your application, assuming you have the engine mounted in the same position a TBSS's engine.

33willys

iTrader: (1)

I took a 5.3 out of a 2003 Trailblazer for my '39 Chevy swap and now I have an AWD pan that yu could use. PM sent.

CoreyH

*****, I sent you an email. Dave, if the motor is mounted in the same spot as a TBSS, assuming if I use the mounts from a TB EXT, the motor should be lined in correctly, right?

tonypaul

iTrader: (2)

Your I6 trans will not bolt right up. You will need to swap the bell housing or get a v8 trans. I have heard that the I6 trans is a weaker trans than the 8 one...

I think you will need a different powersteering pump, maybe a different/better radiator, fuel pump, different routing on the fuel lines.

CoreyH

I plan on upgrading all that stuff while im at it. I did see an article earlier today about the bellhouse needing to be swapped. I'm going to do a rebuild kit on my tranny so was wondering if I get a kit for a V8 if the guts would still fit in my tranny? Since it is still a 4L60E.
Thanks for the info on the fuel lines though, never thought about that

tonypaul

iTrader: (2)

I just changed the trans in my sons I6 Trailblazer last week, while under there I got a good look around to see what it might take to swap a V8.

Pretty sure you will have to relocate the heater core lines as well. I think the easy part will be the drivetrain mounting the hard part will be the wiring.

oh yeah- you will need a V8 torque converter, you wont be able to use the I6 converter...

CoreyH

Thanks for the tip. I will make sure I get a V8 converter as well. I figured the wiring would be a pain. Still looking around here for a wrecked V8 EXT so I can snag the PCM and wiring harness. If I could get the whole thing cheap enough, problem solved for everything!

superdave84

I would assume so, yes.

TipsyMcStagger

iTrader: (1)

Try looking through this.

Tipsy

EDIT: In doing a quick search on Trailvoy, I've already seen at least half a dozen posts that indicate the frames are different between the I6 and LSx.

CoreyH

That sucks about the frame, looks like I'll be doing a little more fabing than I thought!

pdsq98gt

The frames are definitely different. The motor mount perches are different. With the trans changes (bell housing, converter, input shaft), I think it would just be better to buy an SS or an Envoy Denali. You can get an envoy with a 5.3 fairly cheap now days. A lot of those AFM 5.3 engines are oil burners and just need a set of pistons and rings. Could pick one up cheap.

CoreyH

I have asked myself that several times, yes, it woukd be easier to just buy an SS, but my vehicle is paid for. That and insurance would sky rocket for me. Plus I have a daily driver and this is my toy. Being able to build something and say I did it is what I want. A little extra hard work, few curse words, and maybe a few gray hairs wont be too bad for trying this. If it fails and can't be done, at least I tried and can put it all back together and sell the motor that I'm building

Dunningboy

Does anyone have the pinnouts for the underhood fusebox on a 2005 5.3 Trailblazer / Ranier ???

I'm doing a ls swap using the underhood fusebox and I am trying to locate the Ignition wire coming from the fusebox.

dewchugr

See my post in your other thread. I'm using a rainier 5.3 in my project so I've looked some of this up.

Dunningboy

Did you get her fired up yet ??

dewchugr

Just saw this. No, the car is in pieces undergoing restoration.

sean.b

following up on this old thread.. any of you ever get the swap completed? i have most of my parts assembled now, and will be starting in a couple of weeks when my garage is available.