LQ4 piston swap

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Mar 18, 2019 | 05:12 AM

Lou99tahoe

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LQ4 piston swap

i just picked up a 2006 LQ4 and when I opened it up it had the LY6 pistons with exhaust reliefs. I am building the motor for a 2dr 4wd Tahoe swap. I was thinking of picking up some Square port heads and intake but wanna raise the CR too get the extra torque down low. I don’t see myself going FI in the future as I already have a Turbo car. If I swap the LY6 dished pistons to LS2 flat tops do I have to balance again. Is the weight that much difference being that I already have the gen 4 rods and wrist pins. I won’t be spinning this trucks rpm to the roof. Just wanna a torquey fun truck that won’t see any trailer towing at all. Should I jus leave the pistons mill the heads and run a thinner gasket ?

Mar 18, 2019 | 11:02 AM

G Atsma

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From: Central Cal.

Get the LQ9 pistons. Drop-in swap and your compression will go up

Mar 18, 2019 | 11:49 AM

Lou99tahoe

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Awesome I was hoping I didn’t have to balance in my area no one does it for less then 350$

Mar 18, 2019 | 01:19 PM

G Atsma

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The LQ4 pistons are dished 6.7 cc's and the LQ9 pistons are flat tops. Compression will go from 9.4:1 to 10:1. It should still be able to use regular gas

Mar 18, 2019 | 01:30 PM

Lou99tahoe

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Quote:

Originally Posted by G Atsma

The LQ4 pistons are dished 6.7 cc's and the LQ9 pistons are flat tops. Compression will go from 9.4:1 to 10:1. It should still be able to use regular gas

so with LS3 823/821 Heads and Lq9 flat tops I will be at 10:1?

Mar 18, 2019 | 01:46 PM

G Atsma

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The LS3 heads are down 1 cc from the LQ9 heads so the compression might go up another tenth of a point to about 10.2:1, being that LQ9's already have 10.1:1