Ok, so first things first, a buddy of mine is giving me a free 5.3L LS out of a 2001ish truck. Apparently it was a good running motor just high mileage (about 150k) and came out of the truck due to a motor swap. Since it is new to me, I plan to do a rebuild anyway and my first question is, is it easier to buy a top end kit and be done with it or try to buy piece by piece? I am a beginner with motor builds but have been doing a lot of research. I have scowered the threads on here and corvetteforum, I have got a lot of good information from both. Secondly, is it easier to switch the car over for FI or build the 5.3 as a carb motor? I am sure I will have many many more questions as this goes forward but this seems to be a good start for now. My 81 Corvette runs good now and there's nothing pushing me to put this new motor in anytime soon, so I want to take my time, do it right and make it nice. Thanks for any advice you guys are able to provide. The car is not a DD, it is only driven a few times a month in the summertime and I am only looking for maybe 350-400hp at the wheels and has a TH350 trans for now, looking for a 5 or 6 speed or 200r4, but that's a long ways off.

 

imho
get 2x 5.3 engines, both stock. The second engine is either a spare longblock or for spare parts. The Iron 5.3 is great for boost but kind of heavy for just a regular naturally aspirated car @ 400 horsepower. You lose some power because of the extra weight, and the loss of 0.4L of displacement (vs an aluminum 5.7L) together they add up. I'd rather have an aluminum 5.7L @ 380horsepower than a 5.3 @ 400 horsepower if I was never planning to go beyond 400 (no boost or nitrous)


get the right transmission from the beginning (whatever you want) because th350 'conversion' parts and a good converter will set you back too much to be worthwhile in the long run (better just get the right thing now) since you can't re-use the converter on a 4l80e or a 6-speed, which are more ideal (the 6 speed being the most). Some may tell you just use a cheaper converter; I am here to say that the converter is the heart of the car. Without an amazing converter the automatic will never truly perform the way it was meant to. I'd rather have a 6-speed than any automatic with a poor converter.

Fuel injection with these engines is terrific and easy, please check out lt1swap.com they have wiring diagrams etc... For example I pulled a 411 ECU (flex fuel) from a Tahoe in the junkyard with harness for $130, which is alot cheaper than a new stand-alone harness. Then I tuned it with HPtuners which is also cheaper than a stand-alone and works with many OEM ecu (in case you change computers or something later) Low power tunes (400~ or less like you want) are super easy because there is no fudge factoring with the injector sizes (like having to do airmass calculations to correct the computer's behavior for idle or shifting).

5.3 are very cheap, almost free. They also make an aluminum 5.3 called "L33". Ideally if you were set on using the free iron 5.3 engine, You could get it all setup then swap it out later for the L33 which would exactly fall into it's place. That is my plan I intend to use on my car also, since I'd rather "test" a cheap iron motor and "figure it all out" then go for the expensive engine later.

Finally here is a thread I made about my adventure learning about the 5.3
It will show you many of the details you might be concerned about, and I posted some valuable FSM diagrams as well.

https://ls1tech.com/forums/generatio...x-details.html

If the pictures still work that is. Photobucket did something recently to the pictures, I never paid them a dime so they shouldn't work, but somehow or other they seem to be working for me still? Let me know if you can't see the pictures there I have them all backedup.

 

Thanks Kingtalon, if I were going to go buy a motor, by all means I would look for an alum. 5.7. However, this motor is an iron 5.3, which is free. I wouldnt be opposed to 400-500 HP, but even at 35-400 is better than the 195 hp that my vette has now from the factory. Also, I do plan to get a trans to mount up before this motor goes in, I just reread what I wrote in my OP and sorry, it sounded different than I meant it. But my original question was more along the lines of what would be better, a top end kit or buy things separately? Thanks again for your response.

 

If you are going to stay naturally aspirated and change the cam/head/intake sort of thing (and exhaust) you will need to degree the cam and measure the pushrods and all of that stuff... then a vendor will be along shortly to sell you everything you could want to hit your goals. Hes probably typing it up right now for you.

to answer your question directly: yes I think if you are new to the engine in any way shape or form, to get everything as a bundle from somebody who puts together bundles for a living every day.

One of the major issues I keep seeing with engine "mods" is the cam bearings can walk, and many of the sufferers have had new cam bearings installed by a machine shop prior. If you plan to do the cam install yourself I would recommend avoiding machine work at all costs. I don't know how much you've done in the past but also keep in mind the engine needs to say surgically clean inside if it is open. And should never be left open for long, exposed to air. Get in and get out.

 

The answer to your question is buy a complete rebuild kit . The WS6 store has complete rebuild kits shipped for under $700 . They are good quality parts , and will be custom to your build ,example if what flat top pistons or floating pin they will do it same price. If want them over bore same thing. Your not going to be able to beat the value of thier complete package. I challenge anyone to separately price the same or comparable parts for less money.