My 1999 OBS C1500 LQ9 6.0 LS Swap

[ChevyMan90]

Decided to keep the 4L60E and got one for cheap from a 2001 Silverado that needed a rebuild. This way I could run a LS1 style converter and not have to worry about adapting to the older style. A good friend builds them all the time so I got all the parts needed and we did a full rebuild. Then got a 9.5" PI Vigilante triple disc converter. Its supposed to be a 3800-4000




All bolted up!

[kewljay223]

lookin good man. word of caution tho. i see your truck is dropped a bit... im guessin 2/4 or maybe 3/5?? your gonna wanna check clearance on that pan. mine is a 4/6 and i had about 2-3" from ground to pan and was forced to get an ls1 pan for clearance. just letting you know now cuz you will have to pull the motor back out if you end up having to swap it. but anyway keep up the great work!!

[baronsmith98]

This is a nice build man good job. How does that paint you put on the headers look like it will hold up?

[ChevyMan90]

Thanks guys!

kewljay223: Thanks! I think I remember reading somewhere on here (may have been your thread) that the oil pan does sit kinda low. I didnt notice until I brought this motor home that the oil pan I have is shallower than the usual 4.8/5.3/6.0's that I've seen. Not sure if it's because this is a Gen IV motor or what. I'll have to ask a friend of mine. He told me something about it a while back, just can't remember what he said. Thanks for the heads up though! The truck is 2/4 now but I do want to go 4/6 once the swap is finished!

baronsmith98: Thanks man! I blasted the headers to bare metal and primed, painted, and cleared them. All with the VHT stuff. The picture you see with the old headers and ORY was after about 4 years & 50,000 miles of use. They aren't the prettiest, but they have minimal rust. This VHT paint is a lot better than what comes on the headers for sure. I won't be driving this truck everyday, so I expect them to last a decent amount of time.

[ChevyMan90]

This here has been the most exciting part of the build yet! Pulling the 5.7 and getting the LS in! This is 5 minutes after the 5.7 was out. Needed a lot of cleaning!


After pressure washing and adding some paint. Looks freshened up now. Also put on some new motor mounts!

[ChevyMan90]

Finally got it in. To anyone doing this swap with the Trans Dapt adapter plates, make sure you grind the hump off the back of the original cup mounts before bolting them on! Setting it into its new home..


All bolted up!

[ChevyMan90]

Next I got the headers on. The passenger side was a little more tricky than the driver side, but they do fit nicely.


And here is the point where I am at now! Currently its sitting about like this. I had the power steering/alternator bracket powder coated so it looks almost like a new factory one. Also changed the powersteering pressure hose to one from a 1991 C1500 V6. It bolts up like it was made to be there. The transmission linkages are all hooked up and the driveshaft is in. I still need a few more things here and there. I have a new custom wiring harness for a 99-02 truck w/4L60E so that should make the wiring a little easier hopefully. Anyway, Im working on it here and there making progress. But heres how it sits as of now...

[Mickeymotormount]

Looks great. You'll love the LS power!!!

[Lextech]

Finally got it in. To anyone doing this swap with the Trans Dapt adapter plates, make sure you grind the hump off the back of the original cup mounts before bolting them on!

I actually like to put the cups in a press and flatten the hump out.

Jeff

[ShaneOmac]

Good looking truck!! Looking forward to the progress of this.