# 86.5mm Pistons VS 86mm Headgasket

**URL:** https://forums.speedlife.net/t/86-5mm-pistons-vs-86mm-headgasket/131522
**Category:** SON240sx Automotive
**Created:** [February 16, 2010, 4:22am UTC](https://forums.speedlife.net/t/86-5mm-pistons-vs-86mm-headgasket/131522 "2010-02-16T04:22:07Z")
**Posts on this page:** 3
**Page:** 1

<div class="post-metadata">

### Author: ![240newbie](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/240newbie/32/5487_2.png) [@240newbie](https://forums.speedlife.net/u/240newbie)
#### Post date: [February 16, 2010, 4:22am UTC](https://forums.speedlife.net/t/86-5mm-pistons-vs-86mm-headgasket/131522/1 "2010-02-16T04:22:07Z")

</div>

With a set of 86.5mm pistons would the 86mm headgasket work? or do you go with the 87mm?

Thanks

---

<div class="post-metadata">

### Author: ![Cyprian](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/cyprian/32/25410_2.png) [@Cyprian](https://forums.speedlife.net/u/Cyprian)
#### Post date: [February 16, 2010, 8:02am UTC](https://forums.speedlife.net/t/86-5mm-pistons-vs-86mm-headgasket/131522/2 "2010-02-16T08:02:14Z")

</div>

I would have to say 87

---

<div class="post-metadata">

### Author: ![NewfoundlandDude](https://avatars.discourse-cdn.com/v4/letter/n/9fc348/32.png) [@NewfoundlandDude](https://forums.speedlife.net/u/NewfoundlandDude)
#### Post date: [February 16, 2010, 8:44am UTC](https://forums.speedlife.net/t/86-5mm-pistons-vs-86mm-headgasket/131522/3 "2010-02-16T08:44:43Z")

</div>

I posted a similar thread earlier this week about my HG.  
A lot of times, depending on the gasket, they’re already “oversized” or able to accommodate a larger piston.  
For example, my HKS HG only comes in 88mm, and is used for everything up to that size. The Apexi “stock” HG is actually 87mm I think, so check out your gasket, and just make sure it’s as big or a little larger. A mm in diameter is pretty small, but larger works.