:clap:

You convinced me to go with it. They actually use the same piston as the 331 just with the shorter rods. Speaking of the rods, they also told me that they didn't have the rods in stock but they would upgrade mine to the 4130 I beam Scat rod. I looked it up on their website and it's only around $20 more than the Probe 5140 rods the kit comes with but it has a 5.325 length so the piston should only be down in the hole .010 or so and it uses cap screws instead of through bolts.

I have the same rods, and they were kinda "meh" i'd prefer their rods but either way i'm sure you'll be ok. You should see if they wont upgrade you to h-beams, haha.

It's a great facility and everyone was really great, last time I was there picking up my kit the owner saw me trying on this shirt and told me to keep it.

Oh BTW, saw this today
http://forums.corral.net/forums/susp...r-control.html

I'd love to buy that but with this build there is just no way I could.

Just passing it along, I'd like to have it too but it wont work with my control arms. I'll probably hunt down some stock cobra ones.

Little late replying but I might be a bit hesitant reusing the pistons with nicks in them. Worst case scenario, if they are made of a high silicon alloy like hypereutetic castings or a 4032 forging, then they are brittle and you probably already have cracks in the pistons which will propagate over time. Best case scenario would be if they are a 2618 forging; it is a much tougher material and the nicks would only act as a stress riser. Blending out the damage would help but now you don't have a compressive layer from the shot peening process. It is tough throwing out parts that are 99% perfect but it is really just a coin toss without doing some sort of non destructive testing like sonic and penetrant inspection. By the time you get that done, you are probably better off dollar wise getting new slugs. My 2 cents.

The old pistons are Probe SRS 2816-T61 and have been in my 471rwhp Cobra for 90,000 miles running 11-12 psi without any issues. I listed them on Craigslist with pictures of the worst looking piston. I don't think they will be an issue if someone buys them. If no one does though I'll take them to the scrap yard.

Well if you're gonna scrap them....
;)

Those pistons aren't going to be a problem, this isn't on the deck its underneath, where there is the least amount of stress. If the valve reliefs or face or something was all nicked up then yeah i'd toss them. But not on the bottom side. Hell, we use forged 289 pistons all the time cause they're half the cost of the forged 302 pistons you just have to remove a tiny amount of material near the wrist pin. I've had 5 motors like this. One with well over 200k and no issues. Shawn has done countless like that.

Disclaimer: Please don't think I am trying to start an argument. Tone is a difficult thing to portray through he interwebs. Metal is just something that I am extremely interested in and I don't want my enthusiasm to give the wrong impression.

The only problem with the nicks being on the underside of the piston is that that side experiences predominantly tensile stresses versus compressive stresses. Cracks will propagate under lower tensile stresses faster than higher comperssive stresses. There is a good chance that the pistons will be fine for quite some time, but I'm worried about the collateral damage and time to replace if one of the damaged pistons let go. Also, you mentioned that they have 90K on them. Aluminum doesn't have a fatigue life. All aluminum will eventually fail under any sort of cyclic loading; higher stresses and higher temperatures will expedite that. I would be delighted if I got 90K@12psi especially considering there was damage to them.