Justhereforinfo

iTrader: (2)

I'm thinking of swapping out my 4.8 in my silverado for a used 5.7. The plan is to buy a stock 5.7 short block, pick up some refurbished 243/799 heads and have a cam ground to make it ideal for truck use.

My question is, will I be able to use all my existing 4.8 accessories? like oil pan, intake (probably upgrade, but like to know the stocker will work), coils, injectors, pulleys, exhaust?

If not what is needed for this swap?

I did a search for 4.8 to 5.7 swap, swap, 4.8 swap, and 5.7 swap, but found no useful info. I'm sure you guys deal with us truck guys stopping in here all the time with these questions so i apologize in advance if you cover this info a lot. Is there a sticky that I missed?

Thanks

96capricemgr

iTrader: (1)

Well for starters the stock truck intake is BETTER than the LS1 intake and nearly as good as the LS6.

Second if I were gen 3 engine shopping the 5.7l would be nowhere near the top of the list of choices to look at.

In most areas you can find a 6.0l much cheaper, stronger block, that can be bored out for any future repairs or performance build and the heads flow more, as I already said the truck intake is better than the LS1 intake.

Hell a LOT of guys with cars that came with the 5.7l get rid of them in favor of truck blocks.
Believe the truck coils are considered better than the LS1 ones as well.

What year is your truck? This plays into what year engines would be easiest to swap in.

Don't go BLINDLY drooling over car parts, they aren't necessarily the upgrade you would assume

batboy

iTrader: (6)

I see nothing wrong with your plan if you can get a good cheap 5.7 motor (I'm assuming you mean LS1?). Sure, a 6.0 would be desirable, but certainly not a deal breaker. What year is your 4.8? If it's a gen III, then basically everything will fit onto a gen III 5.7.

96capricemgr

iTrader: (1)

The thing is a "good" 5.7l at a reasonable price is a very rare thing. They are more likely to have been on and in most places the price will be double a truck motor.

Justhereforinfo

iTrader: (2)

The trucks a 2003 with 150k on the 4.8, and the 5.7 ls1 is from a 2002 camaro with 75k miles and the guy wants $600. I've been looking for a 6.0 for a while but they go fast in south Florida and are usually a full motor around $1000 with 150+k on them. And I don't need a full motor. If I went 6.0 I would get the ls3 heads.

Good to know about the intake and coils, thanks.

Will the 243 exhaust ports require a larger diameter header?

Justhereforinfo

iTrader: (2)

I think I will pass on this one, and hold out for a 6.0. In the mean time I will lower the truck and get tires.

What are the chances an old 4l60 will hold up behind either of these engines?

96capricemgr

iTrader: (1)

$600 would be a steal for a good condition 5.7l.
I don't think I have seen one here for less than twice that.
the 4L60E can handle a lot more than folks think, now whether your 4L60E can handle it nobody can say.

RockinWs6

WOW 600 for a 75k mile LS1, be very careful with that deal. Usually they go for 1500 plus with 100k.

Justhereforinfo

iTrader: (2)

I'm not familiar with the usual prices, but just to be clear, I'm talking about a stock used short block only. No oil pan, no heads, no intake.

Justhereforinfo

iTrader: (2)

Is $600 still a good price for a 75k mile short?

Justhereforinfo

iTrader: (2)

Just looking for a yes or no answer here. Thinking about picking this up tonight if everything looks good...

PREDATOR-Z

If it checks out OK, yes $600 is good.

Justhereforinfo

iTrader: (2)

We've agreed on a price at $400. So I'm going to check it out tonight.

I've got some measurements from the sticky, so I know the stroke should be 3.662. That will tell me its a 5.7. I plan on spinning the crank to make sure it moves freely, and checking the bores for signs of damage. I also plan to pop a main and rod cap and take a look at the bearings.

At this price, I would think its going to need a rebuild, but what are the chances I could get away with a hone, new set of rings, and bearings?

This will get 243 heads and a custom truck cam, and be a mild daily driver.

Am I crazy for considering a cheap rebuild to last 100k miles? I only want about 380whp...

Justhereforinfo

iTrader: (2)

Picked up the short block tonight. It's casting number shows its a 2002, so that's good, or at least it's not bad. The PO says he pulled it from his friends camaro with 75k miles on it and planned to run it as is, in his 240. I popped a rod cap and the bearings look and feel great. Tight little short block.

I was thinking of marking all the rods, caps, and main caps, and breaking it down. Then cleaning everything and installing new bearings and rings after a quick hone on the cylinder walls.

Does anyone think this is a terrible idea?

RockinWs6

If the bearings look ok no reason not to reuse them. Replacing them Isn't as easy as it sounds. They must be properly set up or you won't be happy.

Justhereforinfo

iTrader: (2)

Could you briefly explain the process? I already removed one rod cap, and re installed the bearing and cap. Just wanna know its ok.

cpolaris502

iTrader: (2)

Ditto^

Is there something else besides just checking oil clearance?

Justhereforinfo

iTrader: (2)

The plan was to plasti-gauge the mains and rods to make sure the clearances are good. If not get the right bearings.

at the very least I wanted to break it down and clean everything, get it lubed up with clevites bearing guard.

Justhereforinfo

iTrader: (2)

I guess I'll buy a book and teach myself. It's either a quiet forum or this topic has been beat to death.

cpolaris502

iTrader: (2)

I've noticed the same trend in replies the two threads I've posted... none/few.