Is that $475 for all six pistons? If so, that's not too awful bad considering it's OEM. I imagine you can get them in overbore sizes as well (.25-.50mm). I'm not too certain a .5 drop in compression is really going to be a big difference. I think it's something like 4% more possible power per point, so if that's correct we're looking at 2% of 263bhp for a drop of 5.26 peak hp. However, I have no idea what it would do to fuel economy, etc. I wouldn't imagine the mitsu engineers bumped it up from the NM version for no reason though.

My advice to would be not to spare any expense. I got what I thought was a steal on a NM for $240 but it needed so much work I ended up sinking over a grand into it, probably more. I did the assembly on my porch: not the cleanest of places but I didn't want to pay for shop labor or rent a place to do it. I ended up getting a little piece of silicone or something in an oil passage on the rear head, starved the lifters, diagnosed, fixed, and in the process dropped a spare lifter into one of the heads that stopped a cam lobe, sheared the pin on my camshaft, and threw off my valve timing. Luckily this wasn't costly monetarily but my car was down and my time was limited. I used a cheaper clutch just to get the swap on the road and it ended up not being strong enough. I didn't buy an LSD off the bat, broke my stock one 5000 miles down the road and was extremely lucky to get a second-hand one for cheap. I had a torn CV boot that I put off because I didn't want to fuck with the intermediate shaft and all that shit. It was working and all, but I had an irritating vibration for thousands of miles. I wanted to lower my car, and knew better than to do it on stock struts but those were blown anyway, so I did it on some cheap ones. That didn't last long and eventually I had to pay for good ones. I didn't have a welding machine and didn't realize I could buy one on craigslist for only a little more than it took to take my exhaust parts to a shop only to have them weld it very shittily to the point that I'd end up just buying a welding machine myself.

Even if it takes a year, it is worth pouring attention over every detail and mitigate any and all unknowns and weak points. I paid for my experience with dollars, sweat and some blood and heartache and am glad I have it, as now I'm a thousand times more set up for serious modification. But if I could go back and do it differently, I would have set myself up for success in the first place.

TLDR: might want to get those OEM pistons if they are that price for the set. Or, shell out the coin for some aftermarkets.

 

i may be swapping down the road. its making me putting off a few of my mods just for the sole purposes for getting things right the first time. i would have the shop working on your block overbore it and go higher compression pistons if youre going to spend the money correctly and once,