LS Swap 101- Educate Me

[joesregalproject]

So I've decided to go a different route with my car. Instead of my original Buick 350 swap, I've decided to go big or go home. I want to do an LS swap. I know they are expensive but its what I want in my car. I need to know some basics first.
1. I know AC is an issue. I'm not running A/C so this doesn't matter.
2. Wiring. What do I do for a harness? Can I send the LS truck harness somewhere to be modified to be a direct plug in for my G-Body? If so, who does this?
3. Is any specific year better than another?
6.0 or 5.3?
4. I'm going to run a 4l60e, so is there a crossmember kit?
5. How much money can I expect to have into this complete swap?
6. Anything else I should know?

 

[Garrett1982]

I can help with a few. Crossmembers are available for the 4L60e. It is the same as the 700r4. You could get a gforce, or the brp or holley, and those can also be included in a kit with headers, oil pans, and motor mounts.
I'm guessing you're looking at truck engines? The 5.3 with an iron block is usually less expensive. The ones from the trailblazers and maybe a few others had aluminum blocks. They would cost a little more. The early 6.0 had iron block and heads, 99-00. 01-06 they had two versions, Lq4 and Lq9. 4 had 9.4:1 compression and the 9 had 10:1. Both had the same aluminum heads as the ls6. In 07 they switched to the Ly6. That is what I have. Same 6.0 block, with 9.6:1 compression, but with L92 rectangular port heads and vvt. The vvt can be eliminated if you wanted. A few companies sell kits. If you are doing a mostly stock engine vvt would be good, it would feel more torquey down low and you would still have a strong top end. I eliminated it but I was going for a more radical power delivery. The 6.0s cost a little more than the 5.3s but both run well. I paid $1300 for my 70k mile engine, including delivery. I didnt get the harness though. See if you can get the factory harness, ecu, and accessories with the dropout. Summit sells complete fuel systems for efi Ls swaps now, and I wish they had that when I was in the planning stages and I might have gone efi instead of carb. Oh well. Definately do your homework before buying anything.

 

[84_SS]

^What he said lol. I'm running the BRP mounts, they fit ok. I have a good friend who's doing a 6.0 swap in his car and he used the Holley stuff (mounts, cross member and headers) and he swears by them, Holley makes a complete header back exhaust system which he is also running and it looks like really nice stuff. You can buy already done harnesses from ebay or places like psi conversions. With these engines being so popular there is a lot of aftermarket support now.

 

[81cutlass]

2. I just did harness stuff this weekend. Its easy to do yourself. There is 2 wires you need out of the chassis plugs: 1 for the OBD port and 1 for the tach. In the black plastic fuse panel theres 4 wires for injectors 2 for coils 2 for O2 sensors 1 for MAF 1 for ECM 1 hot all the time and three grounds. Thats it. Rest of it is not needed for a swap since its AC controls, cruise, ABS, ect. You would need to tune the ECM for swap or buy hp tuners and do it yourself. I just used lt1swap.com and never did it before and figured it out in a couple hours.
3. A 04-06 L33 (high output 5.3 with high compression, good 799 heads, floating rods, alum block) good for like 750 plus they are cheap(ish) since they are "just a 5.3" A 6.0 has a "tax" of 40 more cubes to it. I got lucky and found a longblock for $200 but if you are paying full price at a salvage yard the 5.3 is the way to go. Its not worth buying a gen 4 DOD motor and take the DOD out unless you planned on going for big power and doing springs, a cam, lifters, ect.
5. a complete iron 5.3 dropout runs for $650 in my parts. The good alum 5.3 around $850. Fuel system is $300ish depending on how crazy you go (either EFI monte/GN tank or stock tank with a bosch 044 inline pump) 2wd 4l60e is the hardest part since most of them were 4wd but 300-800 is the trans pricerange. Depending on how DIY you are it can be as little as 1500 or up to 4000 (hot rod garage on youtube just did one for for 4000 minus the car) No engine swap is cheap since they nickle and dime you to death on fittings and bolts so its not much worse than anything else.
6. I have no experience with mounts or headers. I fabbed my own mounts and am using 4th gen camaro headers you can get for 220 that need a little tweaking. Stay before 07 because then you end up with the DOD engines and they can be more challenging to set up. They are stronger though. If you have to notch the AC box or change the oilpan the mount kit you bought is junk. Truck pan sits 2" or so under the crossmember but if you are bottoming out your racecar to need a low oil pan you should slow down. G bodies don't sit low enough to drag out of parkinglots.

 

[dirtyratt]

I have a good friend who's doing a 6.0 swap in his car and he used the Holley stuff (mounts, cross member and headers) and he swears by them, Holley makes a complete header back exhaust system which he is also running and it looks like really nice stuff. .

The Holley system is what I went with .. Little on the pricy side but man worth it's weight in gold .. After moving the frame mount holes. I had the motor and trans and headers in about 45 min .. Very nice stuff .. Ya I have to say it wasn't cheep I have about 5g total in mine not includeding the Dakota digital dash. I did my own harness it was easy and I have efilive so the computer tuning was free .. But they are right it will nickel and dime you to death..

 

[dirtyratt]

What did you do about getting power to the cars lights and stuff? I'm still learning my way thru the wiring part of my build so I'm not 100% sure what to do yet. I've been using mostly lt1swap.com for my harness conversion instructions. I have everything done on it except for the fuse block. PM me if you can.

I used BP automotive pre wired fuse block .. For the car power you just use the old red wire that went to the starter .. I just used a junction block and the extra lead off the positive battery cable to make the connection ..

 

[dirtyratt]

I used BP automotive pre wired fuse block .. For the car power you just use the old red wire that went to the starter .. I just used a junction block and the extra lead off the positive battery cable to make the connection ..

Think of it as two separate systems the car side will be the same as old .. The engine will be stand alone with some influence from the old system for starting and power start signal

 

[Hickrocket1258]

Where are you located? PA? If not, maybe it was someone else that I thought was in PA.

 

[Garrett1982]

There is a 2000 Z28 for sale on CL in the Pittsburgh area for $3500. Has 23k miles with front end damage and bags blown. LS1 and 4L60e. All stock. You could pull engine and trans, radiator, brakes, anything else useful then part out and scrap the rest.

 

[84_SS]

That's a really killer deal actually, and has everything you would possible need