OBS to LSx conversion

**HRV-LS1** · 03-31-2013 10:51 AM

Is there a part number for the brake booster vacuum hose if your putting in a 5.3 into a OBS, using the truck manifold? Do I just buy a vacuum hose to fit?

**droopyzda1** · 04-07-2013 04:00 PM

I had a 2000 Silverado extended cab I sold a couple months back and loved the 5.3 I had in it. Had it for 4 years and no issues. Hence this swap I am now doing to my 1994 C1500 W/T. This is my engine first swap. I am mechanically inclined and I recently pulled out the broken 4.3 with 4L60e trans that was in. I was told the trans was rebuilt a couple years back so I would like to reuse it without spending any extra cash. I purchased a bare 2002 5.3 DBC with basically the block, heads, intake and wire harness that had been partially cut. The person selling it got it from LKQ for their truck but sold the truck before they can put 5.3 in. I got this and other parts off craigslist, so I call this my craigslist budget build. Throughout the pass few weeks, I have gotten a 5.3 flywheel with the concaved center (kind of curved in the center) where the bolts go, a 2002 PCM, 2004 full factory truck intake box and hoses, ls1 intake manifold (may hold off till later), just got a full engine harness and few other things from the internet like dirty dingo mounts and the rear lowering kit consisting of shackles and hangers. I swapped the frame mounts to V8 mounts already thru the lower control gap and it was not that hard as long as U have someone else assisting. I also pulled the bed off yesterday to change the fuel pump to a 1996 and later and since I am there, install the lowering kit. This is going to be a simple driver on the weekends, nothing to be raced. I have a few questions that I see different answers, so here they are:

Can I use my 1994 4L60e with this motor? Will a shift kit or a stall converter help with extra power of the 5.3? Which stall converter would be best?

I read up on some people saying to swap out the inside trans harness to that of one of 1996 and later. Or when I have the PCM reflashed, can I tell the one doing, it to disable the PWM for the older 4L60e trans.

I am looking for an inexpensive way to mount the old 4.3 a/c compressor. Is it possible to use the old 4.3 a/c bracket on the 5.3 with some modification?

Can the power steering pump off the 1994 4.3 bolt on the 5.3 alternator / p/s bracket?

I am thinking of deleting EGR and rear O2 sensors. I live in Miami which doesn't require emmisions testing, but I do not want to be killing myself with all those unfiltered exhaust fumes. Can I simply put on a couple aftermarket cats to filter that out? Will they last even thought the O2's will be deleted?

Can I used the 5.3 flywheel that is concaved ( kind of curved in the center) as is or will I need a spacer for the 5.3 to mate with the 4L60e? Or can I simply use the flywheel off the 1994 with a spacer and longer bolts?

Since I pulled the bed off yesterday I saw that the top of the sending unit has a bit of rust and corrosion. I was thinking of changing the complete sending unit. Can I change the complete unit to one off an '02 5.3 ?

I know I am forgetting something, thanks !! This forum is great and is helping me out with this swap, I just had these questions to verify

Here are some pics .......

ON THE WAY TO ITS NEW HOME:

PARKED AT HOME:

FUTURE WHEELS I HAVE SITTING IN THE GARAGE FOR IT:

PULLED THE MOTOR & TRANS:

THE NEW V8 MOUNTS:

THE NEW MOTOR:

THE BACK OF THE ENGINE:

THE WAY IT LOOKS AS OF 4/6/13:

**YenkoST** · 04-11-2013 07:59 PM

Need to get wheel adapters for those Camaro SS wheels to fit that truck. Nice project!

Also, the ls1 intake requires a car water pump or you'll have throttle body clearance problems.

**droopyzda1** · 04-13-2013 09:10 PM

Originally Posted by YenkoST

Need to get wheel adapters for those Camaro SS wheels to fit that truck. Nice project!

Also, the ls1 intake requires a car water pump or you'll have throttle body clearance problems.

Thanks for the reply. I have had the SS wheels for awhile in the garage even before I got the truck. I will have the adapters made in a few weeks, no rush. As for the LS1 intake, I am going to ditch that idea after reading about and speaking to a few people, supposedly the stock truck intake is better for my application. Plus I do not want to go out hunting for different accessory pulleys and such.

**LS1Nica** · 07-08-2013 08:15 AM

Nice work. i am looking for a donor so i can start my 90.

**Jeebalow** · 03-08-2014 02:52 PM

**ducky** · 03-09-2014 01:54 PM

Awesome list! Really appreciate you compiling these

**Jeebalow** · 03-09-2014 02:00 PM

Originally Posted by ducky

Awesome list! Really appreciate you compiling these

No problem. I have used these all during my swap so I figured it may help others as well. Just wasn't sure where to put them.

**Mang213** · 03-15-2014 11:34 AM

I'm going to be leaning on this thread pretty heavily in the near future. Great detailed info

**Goldhawg** · 04-18-2014 05:28 PM

What are the normal header choices for 4WD tahoes?

Thread: OBS to LSx conversion

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