Long story short, I have an 02 LQ9 6.0l that got water in it, the cylinders got some pitting in them, and there is some heavy egging in the bores. My machine shop is a few weeks out, but he wants me to get my pistons in advance. I'm doing a cam only build, flat top pistons, 799 heads, 1 3/4" headers, & tbss intake with 92mm throttle body, so nothing wild. My main goal is reliability & longevity, so with that in mind, which pistons would you go with? The 3 I'm looking at are silv-o-lite(never run them), speed-pro(have run in the past with good success, but never long term), and mahle(I know they made them for GM, but have heard mixxed on there aftermarket). The cost doesn't bother me, but getting a piston that will last for the long haul does.

 

I did the diamond pistons and they are holding up well so far. I have about 15k on my 408 with them.

 

Make sure whatever pistons you get, DO NOT have the extra .020" of "rebuilder" deck clearance. Diamond, JE, etc. would be my first choice. They're forged besides. Next choice would be the Keith Black hypers. SpeedPro is the old TRW line, which have the lower deck height. Not sure about Mahle replacement ones.

 

I used Diamond pistons In my stroker as well. No issues with like 20k on the clock.

 

I used 4032 Mahle pistons for added strength over stock and longevity vs 2618 pistons.

 

I'm having the block bored, squared, & decked on a rottler, so I want reduced compression height. This is a basic street build that shouldn't see but 500hp on the best of days, I need it to last for a long time, so I'm sticking with a hypereutectic cast piston. From what I can find, Silv-o-lite & Mahle are .010 reduced and Speed-pro is .015. The only cast piston I found with a stock compression height was moresa. I was leaning towards Mahle because the OEM pistons were Mahle, and they've proven themselves to hold up to thousands of miles of abuse. The cost don't bother me, I want it to last.

 

The Mahle aftermarket replacement cast pistons are over priced.

I was only able to get Silv-O-Lite when I put mine together 2 years ago.

The Speed Pro's work as well. A buddy of mine had some in his build. But The block was not Honed properly and he always had an oil consumption issue. Also he didn't have the block decked and when I checked it the pistons on tear down, they were down in the hole -.009 below the deck. With about 30K on the clock they still good to go for another engine , of course I would put fresh rings on them.

Make sure you have the Block deck surfaced and when you mock everything up, check the clearance. You want to be out of the hole a few thousands. If your in the hole you will have detonation issues and be down on power. That engine never felt like it was making the power it should have.

 

My only experience is with OEM and wiseco. I've never lost a piston as the original failure point. My pistons are usually a casualty of something valvetrain related. Broken springs, broken timing chain, sheered off cam bolts and once a shattered a rod sent a piston into a collision course with the valvetrain. I usually just knock off the high spots with a roloc pad where valves meet and slap those bitches back in. I have at least 2 pistons in my current 408 that have been introduced to valves.

my point being, they are probably all just fine as long as the ring gap is good and the tune is right.