3500 heads & intake manifold on a 3400

[berettaguy]

Hi, I've been running a 3400 from a '99 Grand Am in my '91 Beretta for a decade now, and I've been pretty happy with it. I'm considering swapping over to the Stage 2 3500 heads and Stage 2 3500 upper and lower intake manifold from WOT-Tech. I'm aware about the massaging needed to fit the 3400 FPR with the 3500 UIM, and I'm aware that the CCP will just be hanging unsupported. I've got a couple more questions that hopefully you guys can help me with:

1) will my existing pushrods work with the 3500 heads or will I need longer/shorter ones?
2) will my 3400 throttle body and bracket work with the 3500 UIM? If I remember correctly, I used a throttle cable box from an older Quad 4 automatic to mate it all up.
3) people who have gone through this swap, was it worth the hassle? Was the power gain noticeable & would you do it again?

I appreciate your input and any other advice that I should be aware of.

Thanks!

[koolcamaro]

1) According to RockAuto.com, a 2001 Grand Am 3.4 and a 2004 Chevrolet Malibu 3.5 both use the same size intake and exhaust pushrods. Intake: 5.750 Exhaust: 6.074

2) No, you will need an adapter to make the 3400 TB work. I'm assuming you have the TCE throttle body to not want to upgrade to the 3.5 TB?

https://wot-tech.com/lx5-65mm-tb-adapter.html

3) I have a 3.4/3500 in my 95 Camaro so I'm a bit different although I think my experience is relatable. Before I successfully completed the 3.4/3500, I was running a fully ported/polished 3.4 cast iron head setup which flows on the same level of a 3100. It was fast with the ported 3.4 heads, but there was a night and day difference with the 3500 heads. Especially combining them with a full port/polish and a cam.

[koolcamaro]

My bad, that link to the throttle body is the wrong one. That adapter is for adapting a LX5 TB onto a 3400. WOT-tech might sell the adapter to adapta 3400 TB on a 3500 UIM. I know I've seen it somewhere. If they don't sell it then you can check with British Car Conversions or Milzy Motorsports.

[berettaguy]

My bad, that link to the throttle body is the wrong one. That adapter is for adapting a LX5 TB onto a 3400. WOT-tech might sell the adapter to adapta 3400 TB on a 3500 UIM. I know I've seen it somewhere. If they don't sell it then you can check with British Car Conversions or Milzy Motorsports.

Thank you for the response!

[diabolical1]

How did your project turn out? Do you have any photos of your throttle setup?

[koolcamaro]

^Talk about bringing a thread back from the dead

[diabolical1]

Well, truth be told ... it seems all of these threads are dead, just varying degrees of necrosis. It was something like the fifth thread on the first page.