3500 heads

[bwwelk]

I was wondering is it true that the 3500 heads will fit and or bolt up to a 3400 ga motor...How much gain in hp would there be with swapping them???

[torq455]

yes they will bolt up. you will need the intakes as well. not sure about hp gain, however, the stock 3500 is about 210 hp and 220 tq.

[SappySE107]

I think its 200 hp for the 3500 version that you can use parts from. You have to use the complete top end and it requires some mod work to get the injector rail setup to work. Im working on all this right now.

[PCGUY112887]

Starts to seem easier to swap in the whole 3500...
Should be perty much the same as the guide off 3400swap.com for us 3100 people (I think at least?)

[SappySE107]

You have to use the external crank trigger setup or swap the timing gear ring off the stocker for a 7x version, plus an adapter to change the distance for the CPS.

The 3500 is an awesome looking engine internally as well so yes, you may as well just swap the entire motor in there.

[bwwelk]

So all I would need would be the heads ,UIM and LIM ..And you said the 3400 Plenum can be used with that ,, WOULD THAT BE ALL THAT I'D NEED TO SWAP THE HEADS??? I have done alot of work on cars ,but this I have never done SO just askin to make sure...

[IsaacHayes]

search the 3500 threads on here, and read up and it will tell you more. Your fuel rail will have to be used and the FPR will hit the 3500 plenum neck, and have to be ground so far to clear that you have to re-weld it. Or you can use the 3400 plenum on top and not have the issue but it doesn't flow or make as much power as well as the 3500 plenum.

This issue is different than when swapping a 3500 plenum onto a 3400 lower, you still have to grind the 3500 neck a little, but not so much that it breaks through like when using both 3500 plenum and lower. Just throwing that out there so you don't get confused if you read about that.

You need to make sure the 3500 stuff you are getting is from the 3500 that DOES NOT have VVT.

[bwwelk]

Hope you don't mind me askin but what does VVT mean .. 3500 motor from a Olds Intrigue is the same setup as 3400 right or am I wrong on this????? Was just thinkin about goin to a Junk yard and try to find a 3500 that has lower miles on it and just use the parts from it, that way I wont be payin so much ..

[SappySE107]

No olds ever got a 3500. variable valve timing, and you won't likely find one of those cheap anyway.

[bszopi]

The 3.5L in an Intrigue is a totally different beast. Its not even a 60* engine. VVT is variable valve timing. The 3500s that you are looking for were first available in the 04 Malibus.

[bwwelk]

Oh ok ..I see the Old Intrigue has a 3.5 but its dual ovr head cam i didn't realize that until i just looked it up.