Hey guys, i'm the new owner of an 89 rs. I am looking to swap an LS series motor into it, and i have been searching ls1's, but they are seeming to be too expensive. My question is that i can find a 5.3L for way cheaper and i have heard that the same cam and heads will work for either of the motors. Is this true? also, how hard is it to swap the 5.3 (or 5.7) into my RS? thanks. by the way, great site. Ive been a member for only a short time and i have already doubled my knowledge on third gens. -Michael

Yes, it is true, but it is still costly in the end. A LS swap is still not "cheap" like a SBC to SBC swap.

Welcome aboard thirdgen.org.

Read the sticky about LS1 swaps in the top section of this forum to get an idea of what is ahead of you.

There is a thread on ls1tech about doing an LSx swap for $1500 using the 5.3's. But, he's not putting them in 3rd gen f-bodies so he can keep the truck intake, oil pan, exhaust manifolds, and accessories. Add all of that to the cost of the engine when comparing it to a 4th gen f-body engine, then you can figure the rest of the costs and swap difficulties are a wash.

If you're going to use a truck engine, might as well make it a 6.0. They go for only a little more than the 5.3's.

I agree, unless you want the high rpms from the 5.3, the 6.0 is the way to go. I am looking at doing the same swap myself and I am torn between these two engines. I have heard with a head rebuild, cam swap and a few other things, you can crank out some outstanding power from the 6.0. A BIG expence in going to be headers, they run $800+ for a set of long tubes, but you can get away with 98+ fbody manifolds. Anouther option that some people choose to do is convert thier LSx to carb. You can run a traditional distributor or MSD makes a easy to install wiring harness and ingnition box to control timing. I will probably go with this route myself just because I do not want to mess with coputer tuning.

Welcome to the board, post some pictures of you projects as they progress.

Computer tuning is cheap in comparison. Also not likely to be needed.

Depends on application and modifications. Also, it is alot easier to tune at a track with a carb then with FI, unless you have all the programs and really know what you are doing. Also, it is cheaper to make big amounts of HP with a carb then FI. There is no worrying about high pressure injectors, larger fuel rails, and higher performance fuel managments systems. However, if you are just droping in a LSx motor and leaving stock, it is cheaper to keep the FI. I think to go carb it is going to cost me and extra 600+ easy and I think I am being modest. However I do think it is neat to see someone carb one of these, just my opinion.

I think an LS1 pullout is probably cheapest. Sure it's more initially than a 5.3 but you're going to have to buy an LS1 intake, fbody accessories, fbody pan, windage and pickup etc.. anyways. Unless you can do the whole swap for dirt cheap it wouldn't be worth it anyways. Most people can't seem to do it dirt cheap so an extra $XXX for the LS1 versus a 5.3 or whatever isn't going to be a huge deal when you look at the overall price of the swap.

Well what are the different in deciding a cam choice between a 5.3 and a 6.0? i have wondered about the 6.0 but i didnt know what the difference was in the internals as compared to the 5.7 LS1 or the 5.3. I found a cam from texas speed and i would like to know if it will work or not. thanks alot guys, this forum is helping me out ALOT.

-Michael

My point exactly.

Highly unlikely to need to tune at the track. Unless you're going to the track to tune.
Gen I SBC's, I'd agree. LSx, not true.

The OP hasn't indicated any particular use for the car. If we assume driver, then carb makes absolutely no sense whatsoever.

I think you're underestimating, unless you have most of the parts already in hand.

I don't see anything neat about it, personally. Plenty have already done it. A couple in particular are very fast, but they're track cars, not DD's.

Learn new stuff everyday, I am looking at creating a track car.

When you're talking about a GenIII block (LS1, LS6, LQ4, LQ9, 5.3L whatever it's acronym is...), a cam is a cam. It's like an old school sbc, cams are interchangable. Now, the behavior of the cam is going to vary slightly depending on which displacement you're going with. For instance, the Texas Speed 224R is a *relatively* small cam, and when you put it in a 6.0L it's nature will tone down slightly more. Bigger cubes tend to want bigger cams to get the same effect as a smaller cam in a smaller cube block. I put Texas Speed's MS4 cam in my 6.0, some say that is a nasty big cam, I say so what, and besides it's going in a 6.0 not a 5.7, so it will tone down slightly from what you'd experience with a regular LS1.

right now just get it built with a 5.3. Later you can start on a better LSx using an L92 block, CNC-ported L92/LS3 heads, a stroker crank, and whatever else you'd really like.