LSx Swap Guide

Alright, I had a handful of do-it-yourself guys wanting more info on how to swap in an LS-series of engine on a limited budget. I will try and help shed some light on installing one of these in about anything on the lowest budget possible. Dependability, great power output, mileage and the cool factor all can come at a very reasonable price if you are willing to work a little for it. Eventually I will be adding a full parts list that can be purchased here, so you can get all the correct parts from one place, along with technical support to make your swap a success.

First off a little about the engines I will be referring to. In my world I refer to either the 4.8, 5.3, 5.7 or 6.0 engines as LS1 as they share the same platform and most parts with the actual 5.7 aluminum RPO LS1 engines. I rarely do ACTUAL LS1 swaps and here is why. The two main advantages a Camaro/ Firebird/ Corvette LS1 have over a truck 5.3 for example are that the aluminum block weighs 65lbs less and they usually make around 10 horsepower more. These two factors do not warrant the big difference in price to me. There have been dyno tests were 5.3s were swapped in place of 5.7s and with all parts the same (intake, etc) they usually made 9-10 horsepower less. This is obviously NOT a large difference. I'm not bashing a true LS1 by any means, but the 5.3s can usually be bought for 1/3 to 1/4 of the price, so I tend to use them.

That said.....

With some digging around, you can usually pickup a complete 5.3 for anywhere between $500-$850. The way I usually get them is top to bottom, with truck intake/ rails/ injectors/ coils. They usually do NOT have starters, alternators, power steering, etc. I stock some of these and may be able to supply you with an engine, and I can usually ship them reasonably.

The next biggest expense is usually the harness, which you have different options. Either harness can be made to work, be it from a truck or a LS-car harness (Camaro, Firebird) The biggest differences are that the trucks use a different injector plug type than the cars and the truck harnesses lay out differently. I try to avoid the truck harnesses as much as possible due to the odd layout, they are harder to make look nice and they are wired a little more complexly than the car ones (more keyed power sources) Here is where you have to decide what direction you are going to go, plan on leaving the less attractive truck intake (still make good power) or switch to the car style intake/ rails/ injectors to make it look more like an actual LS1. A stock harness usually will run around $150-200 dollars and you will then have to spend 3-4 hours cutting it apart/ figuring out the wires that won't be needed for your application and removing them and finding the wires you will need to connect to make your swap run. This is not a very difficult task, but it does require some patience and a good source of info, such as the LS1tech.com - Conversions and Hybrids section.

This would be the cheaper route to go if you are somewhat confident in wiring, the other route would be to buy an aftermarket or already converted harness. I personally sell a very high quality wiring harness laid out to just about any spec. These are made with the correct length wires to allow for near limitless ECM placement and the overall layout more pleasing to the eyes. I've used many of the aftermarket harnesses, and to be honest have used these for the last 20+ swaps I've done because they lay out so well, and are incredibly easy to install. It would take a lot of work to modify every wire on an older harness to make it layout as nicely as one of the custom built from scratch harnesses. Prices start out at $550 for a non transmission harness and go from there. Contact me for info.

The next item to consider is what transmission you plan on running. The LS engines will work with any older GM trans with some considerations. TH350s/ 700R4s/ TH400s work by using a GM part as a flexplate spacer and bolts to place the flexplate at the proper spacing, and this part provides a place for the converter snout to engage, using the original converter. The thing to consider is the downshift/ TV cables associated need to be addressed. Companies like Bowtie overdrives, etc have pieces to make them work. Obviously the 6-speeds/ 4l60Es designed to be behind the LS-engines work easily with the proper harnesses if your budget allows.

Next would be the fuel system. The easiest way to do this would be to use an inline Walbro pump sold all over the net, usually around $120 and the corvette filter-regulator combo. There are many options here depending on your vehicle as far as getting the fuel to the pump. You can pull your factory sending unit and find a way to mount the pump to the sender and install in tank, or maybe even an aftermarket vendor makes a sending unit for your application to do just that. Other options including welding a sump to the bottom of the tank and feeding from there. Next would be installing a fuel cell or even an aftermarket tank designed for EFI use in your application. Some even just mount the pump and pull fuel through the factory pickup. This is usually okay for lower horsepower (stock swaps) and certain pumps, as some don't like pulling fuel very much and might not last forever. After the pump, you feed the corvette filter/ regulator which then has an output that you run to the fuel rail and it also has an output for return fuel back to the tank which just needs plumbed into the top of the tank. The truck intake and fuel rails includes a regulator so you can just run a line up to it and a line back from it returning unused fuel to the tank.

The only other variable here is what accessories you need to run on your engine. Of course there are vendors out there like March, Kwik Performance etc that sell complete accessories setups that are nice, but pricey, which doesn't fit into this budget writeup. I usually am doing hotrod style swaps that often only include an alternator. These are fairly simple, I usually use GM CS-style alternators, found in TBI/ TPI style 4.3-5.0-5.7 engines. These are pretty affordable, work well and are easily replaceable in case of failure. Making mounts out of simple metal (3/16s bar stock-3/8ths round stock) doesn't take too much skill. Just mount the alternator out of everythings way in your swap and most times you can even route the belt to use the factory tensioner. I have done many this way and even some with power steering and used the factory tensioner with perfect results. None ever took more than two hours to figure out. For the non creative types the easiest way to do this is to hold a straightedge across the balancer and hold the alternator up to it in a good spot and find a way to tack a bracket in place to hold it temporarily and then build some easy brackets (I love using the round bar) to mount it, it doesnt even need to adjust if you use the factory tensioner. Of course using factory LS1 brackets/ accessories is always a possibility if they fit your application and are available for use. The thing to keep in mind is that the truck/F-body/Corvette all use different accessory spacing in regards to the distance from the pulley to the block, the trucks stick out the furthest, the F-body is in about 5/8 from that and the vette is in a little more. The total difference between all three is around an inch I believe, but it is enough to make obvious bracket issues if trying to mix and match parts.

Now just add whatever YOU might need for your swap. Things to keep in mind are:

Do any of the stock LS style manifolds fit your chassis? There are many choices, including those from the trucks, F-body, vette C5, vette C6, GTO, even the front wheel drive style ones. If none of these fit you may be left going to an aftermarket vendor that makes swap headers, or having a set made. Obviously the cost can vary greatly here.

The other thing to keep in mind is the oil pan. The LS engines came with many different pans. The truck pans resemble old school SBC style but hang kinda low. The F-body pans are lower profile but extend further forward. Research will have to be done for your application.

The best part about the internet is that almost any combination you can think of for any swap has been done or tried, so a little research can go a long way towards planning your swap.

Good luck guys and don't get discouraged, these swaps are not that hard and they are great when finished.