huge dessison maker

[monstergarage]

i wanted to know if replacing the intake on the 3.1 with the 3.4 intake will make more power will i have to switch heads too?

[geoffinbc]

Yes you can change them. No you wont have to change heads. The 3.4L intake is better but I am not sure how much.

[johnnymossville]

The 3400 intakes are large port and the '97 3100s are small port. Also, the 2000 and later 3400 upper intakes flow better than the earlier ones. Plus you could use the 3400 TB, although then you would need to free up your exhaust flow to take advantage of the increased intake flow. Engines are basically air pumps, which means if you put more air in (better intakes) you will put more air out.

[geoffinbc]

Well I was talkin Iron head stuff which I see now is wrong since he has a 97 Lumina. So the post is about 3100 and 3400 intakes. But in any case the same rule applies.

[monstergarage]

i have another idea about changeing the engine to a 3.4 dohc how can i go about that?

[candychevy87]

dual cam heads wont fit on single cam blocks

[monstergarage]

so would it be worth the power gain to change engines tranny and computer?

[Sidewinder]

What car is this for?

[bszopi]

Per his Vehicle Information dropdown, its a 97 Chevy Lumina with the 3100.

[montess408]

if i where you i would stay with the push rod motor way more dependable !
if you bottom end is good just do a 00+ top end swap and if your motor is tired do a 3400 motor swap and start from there

[Sidewinder]

Per his Vehicle Information dropdown, its a 97 Chevy Lumina with the 3100.

Ah I forgot about that thing.

As montess said above, you can swap a complete 3400 top end onto your 3100. From what I understand you do not have to swap the 3400 heads if you don't want to, but I believe the ports won't line up properly with the 3100 heads and it isn't optimal. The 3400 heads have larger ports, and an all around better cast.

I also believe if you switch to a 3.4DOHC from any year you are going to have to rewire the car because the Pushrod and DOHC motors are very different. If you are looking for performance, the DOHC is hard due to its lack of aftermarket.

An almost direct swap in would be a 3400 motor which will give you a better base, your other options are a 3400/3500 hybrid or a straight up 3500.

[3400-95-Modified]

3400 and 3100 head ports are exactly the same, the valve is .02 larger but thats not enough to help/hurt something... It's the upper runners that are the biggest difference.

[Sidewinder]

3400 and 3100 head ports are exactly the same, the valve is .02 larger but thats not enough to help/hurt something... It's the upper runners that are the biggest difference.

I do learn something new everyday

[monstergarage]

would it be cheaper to do a the 3400 swap or just bore the 3100 and top end swap, with some cam and valve work?

[3400-95-Modified]

I dont know if you can bore a 3100 block to 3400 size, and also cam and valve work on a 3100 with 3400 top end will do more power than a 3400 alone.