Blackta24

I have a lq9 shortblock and I wanted to know what is needed to make it a 376 as I would, basically, like to have an iron ls3 and will be running ls3 heads/intake

redtan

iTrader: (5)

Bore it to 4.067?

Blackta24

Can I use ls3 pistons?

redtan

iTrader: (5)

Sure, but why would you use a cast piston when much better choices are out there for similar prices?

Blackta24

That's a great point. Would you have a piston recommendations? Car will be na and looking for 450-480 rwhp with h/i/cam

drenner43

iTrader: (4)

and if you're boring and buying new components anyways why not spend a little extra and buy a new forged crank and build a 408 with a 4" stroke and 4.030 bore. From everything I've read not all block should be bored to 4.060 anyways and 4.030 is safer.

87silverbullet

iTrader: (11)

4.065 is the stock bore for an LS3 and I don't think it would be too advisable to take an iron block .065 over. Thats alot to take out.

If you did do it with stock LS3 internals you would end up using a 58x tooth crank and you would have to get that changed, which should be done by an experienced person, or get a converter box from Ligenfelter. Then to machine everything and buy an LS3 rotating assembly, you might as well buy a 408 rotating assembly from TSP and it will damn near come out the same. They have them at a starting price of 1695.00.

KCS

iTrader: (20)

I'm doing the same. I'm using stock LS3 rods and pistons with the LS1 crank out of my old engine, so my rotating assembly was almost free. The stock pistons are actually pretty nice, and they'll hold up to the power level you're shooting for, so I don't see why you should need aftermarket pistons.

My block is already machined, just getting the crank balanced this week so I can mock it up and cut some valve reliefs.

Sales3@Texas-Speed

iTrader: (2)

I couldn't have said it better myself. OP, we have several options if you are interested. Please feel free to pm me or give us a call, we would be happy to discuss those options with you, and help you find what you are looking for.

litle88

iTrader: (20)

+2 on 87's advise!

Blackta24

Well I plan on using the stock crank and rods from the lq9. And new pistons, rings, and bearings.

KCS

iTrader: (20)

Well, you're not shooting for a lot of power so the stock pistons would be just fine, but if you want to go with aftermarket pistons, you may want to look into a 4032 alloy. They tend to last longer and require less piston-wall clearance than comparable 2618 alloy pistons. TSP sells a 4032 alloy Mahle piston, pn 168-L923400 for a 4.065" bore for just over $600.

On the other hand, if you want to save some money and get more bang for your buck, you can find stock LS3 pistons for cheap, if not free, and spend about $150 on rings and be done. They're meant to last and they have a lot of nice features like coated skirts, anodized top ring lands, and oil reservoirs in the pin boss that you typically don't see in off the shelf aftermarket pistons. The downside is they won't have valve reliefs.

midevil1

iTrader: (17)

Don't know whats wrong with going .065 on a 6.0 block. Done it twice and made in the 600+ range with no problems. One of the motors has 80K hard miles on it at 7200 RPM shifts.

Blackta24

Yeah, I was reading in another thread that a 6.0 block could be bored safely to .065.

Sales3@Texas-Speed

iTrader: (2)

Although it has been done, if you are going .065" over I would recommend having the block sonic checked.

KCS

iTrader: (20)

What wall thickness would you think is safe for what power levels?

87silverbullet

iTrader: (11)

I think LQ9 pistons and rods are press fit and the LS3 pistons are a floating piston so you might want to check into that also when mix matching parts from a Gen 3 and Gen 4 engine.