So, some purists will probably disagree with what I am about to do.....First the back story.... So about 2 months ago I packed up my tools and quit turning wrenches for a living. I took a desk job as a Warranty claims adjuster for a new GM extended warranty, and moved to Dallas. Well with this new job came more money so now its time to spend spend spend on the 1LE. Well I went to the track one weekend with my bracket racer buddy. I decided to run the 1LE and man let me tell you, those 9.3 sec 1/8 mile passes left a little to be desired. So I decided I need more power, the 1LE DESERVES MORE POWER! Well I now have that power or at least the potential for it. I am the proud new owner of a 76k mile 2005 LQ4/4L65E combo from a t-boned silverado.

So over the next few weeks and months Im going to be gathering money and parts so that I can acomplish this swap. Now Im the second owner of my 91 L98 1LE, and it might be wrong to molest it, but you know it just seems right. I have had several other thirdgens, always wanted a 1LE, it was my dream car, and I have it. I have absolutely 0 plans to ever let it go so the fact that Im going to do such a drastic change to it means little to me. In my mind I have a 1LE, "the king of the the third gens" and damnit it deserves more power and respect! So here are my plans that may be altered.

UMI Kmember and A arms, spohn trans xmember and torque arm, hawks headers (i know ill have issues with the trans xmember)... stock 10bolt for now (it does have an aluminum cover for what its worth lol) when the 10bolt goes ill see about a 9inch...
For the engine i think ill just pick up a pull off ls1 intake and install the motor stock. after its in and running good ill save some cash and I want to swap to some l92 heads and ls3 intake, i know the compression will still be low but ive seen a cpl builds making over 500fwhp with the right cam. I would be extremely happy with 400hp at the wheels... Plus with these heads i have alot of room to expand if I ever get around to building the bottom end. Ill put a decent stall in depending on cam specs and all but id expect 3500 or so..
Well I have lots of parts to buy so I better get going on that, ill post as things come in and progress is made...Just one more LSX swap...

 

Good luck with your swap... it is your car to enjoy! More power = More fun!

I would only consider a manual transmission, but that is just me. If you have a son or daughter a family project is also a great bonding experience

 

Yeah I almost swapped in a t56 when i broke the 700r4 before, but i had it built and kept it auto. I will be staying auto because I will be running some bracket races with the car. Plus my DD is a standard and I get tired of shifting lol...

 

400 will be easy. I used an LQ4 LS2 heads LS6 intake a stage 3 trick flow cam. After some more tuning 2 weeks ago I'm at 436 RWHP. And thats through an Automatic and a set of SW 1 3/4 headers with 2.5 collectors. Not the 3in like most people run. (open cutout though)

 

if you keep all the old parts motor ect theres no problem with it

you said a LQ4 and 4l65E? if its the LQ4 you should have a 4l80e from a 2005 if its a 4l65e then you might have a LQ9 is it a cast iron block and if you can take a peek in the plug hole and see if it has flat top or dished pistons

 

just took a LQ4 got LS3 heads for 350 a piece from SDPC a 229 ish cam (just a bit more than a LS6 hot cam) and LS3 intake and the motor made 450 through a tko 600

do not spend money on LS1/2 heads when LS3 heads are just as cheap and flow more as cast than a set of ported ls1/2/6 heads

 

Heads only ran me 300 total with upgraded springs and i already had an intake waiting. if I was to do it again I would find used LS3 heads and a used intake but then again i did my swap 4 years ago.

 

at that time they were the good stuff but now the the LS3 items are easier to come by you cant beat it