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decking heads


broncobuckinaround

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I suck at math and can't seem to find any correct info. so it's the 2.9 and I was curious to know if it has ever been done. decking four hundred thousandths off the head surface and putting in the 2.8 pistons. I want to raise compression and add headers for a little more power. and later on do the 4.0 swap.

thx for all the info
 


JoshT

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If you are already thinking about a 4.0L swap, then the gains to the 2.9L won't be worth the cost or work.

I havent done it but it jas been done. Adding the pistins will bump you to around 10:1 compression ratio, decking the heads might take it a little further. Doing this you'll basically be rebuilding a motor you already want to replace. You are looking at about a 14 HP gain at best, probably need a tune, and having to run premium gas. By the time you really add up the cost of machine work and parts, you are well on the way to the 4.0L swap (if not past it) and will still have less power. If you get everything lined up in advance it probably won't take any longer to do the 4.0L swap than to rebuild and reinstall a 2.9L.

The 2.9 headers won't fit the 4.0L so that's more money tossed when you do the motor swap.
 
adsm08

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Agreed. You can throw all the money and work you want into a 2.9 and it still won't be as good as the 4.0 for power. No replacement for displacement.

Also, all the work to take the engine out, put it in, etc will be repeated.
 

broncobuckinaround

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Thx guys. That's good to know. I was hoping for it to really boost better power. But since it's not worth it ill just go ahead with the swap. Ill rebuild the 4.0 instead.

Any good power boosters ideas for that motor
 
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