Motor Options?

[ThunderBolt]

Well guys it's been a few months since I gave ole' number 7 a new piston.. and I think some of my problems are coming back. My truck isn't smoking out the exhaust like it was when the ring land broke but there is still a little blow by. I've noticed that the idling has been a little rough at times; I may also be loosing compression. I'm thinking more of the pistons/rings may have been damaged. I'm not quite sure about how to go about this issue.. I could rebuild the rebuild my 5.3 to an iron block 5.7, buy a junkyard 5.3, or buy a junkyard 6.0. Each one has it's advantages and disadvantages; however, I'm looking for the most bang for my buck though! Since I'm running boost I'd like to rebuild my 5.3 to an iron block 5.7 with forged internals but I don't think I'll be able due to the fact that I'd have to buy a rotating assembly ($$$), and different heads to lower my compression ($$$), not to mention machine work ($$$), so this might be out of the budget. Unless I could use a stock rotating assembly.. would this be suitable? My other options would be getting a junkyard motor.. I've found a few 5.3 motors ranging from $600 to $750 with anywhere from 72k down to 40k miles. I have also found a few LQ4 6.0 motors.. $900-116k miles, $1100-96k miles, and $1300-84k miles. I wanted to get some opinions before I made any purchases.

Thanks,
Trevor

[gTeran1]

ill trade u a 5.3 for your turbo
haha


the price for the motors are alittle too high,no?

[Sleaper]

I'm going through the same thing right now too! It sucks but here's what costs I am going to have. I'm boring out the 5.3 to a 5.7 and going with forged internals. I'll reuse the stock crank (and possibly rods) since they are pretty stout from the factory. Everything else will be top notch, rings, forged pistons, ARP bolts and studs, head gaskets, valve job on heads completely balanced and assembled for about $2,500. 317 heads can be found for $150 to help lower compression on the 5.7. You can get a 5.3 in good shape for around $400 for a longblock and $250 for a shortblock, even cheaper if you look around. A 6.0 will cost more but still can be found for around $700-900 for a turn key motor. If you go 6.0, get ready to upgrade the trans to an 80e if you haven't already since you'll have too much power for the 60e.

[jcormier89]

i posted a craigslist add in racers lounge for a 6.0 long block that's being sold for 900...although its in Houston and you're in Georgia

[gTeran1]

http://www.ls1truck.com/forums/sale-...l-harness.html

[ff_jeff]

I see it this way. A 5.7 can make 1000whp. so can a 6.0. Stock 6.0 is obviously at the advantage. But I would rather have a forged iron block 350 than a stock 6.0. If you get forged internals, and decent H,C,I... boost would be lovely.

[ma.racing]

true true

[Show&Go]

If you can afford it a iron 5.7 would be great. But if your only choice is a junkyard motor I would spend the few hundred extra and pick up the 6.0

[r.barn]

All you need to rebuild your 5.3 is new pistons.

stock crank is fine
stock rods are ok, wouldnt hurt to upgrade

No need for new heads, just get dished pistons.
dished pistons is best way to drop compression anyway.

[ThunderBolt]

I was trying to find out a little information on prices about boaring my 5.3 into an iron block 5.7 so I called this engine builder that's known for really good work and he said the cylinder walls would be too thin. I know there's been people to do this but why is the engine builder saying no?? He said it's only possible to bore 60 thousands over without getting the cylinder walls too thin.

*Just talked to another builder and he said that the lsx blocks have a lot more cylinder wall thickness; which was what i thought. He also said he could sonic test the cylinder walls to make sure that this will work. Looking at around $700 if i take him just the short block and parts.