Everything i found when i searched says the 2.8, 3.1 and 3.4 iron heads are basicly the same thing as far as intake and exhaust port and bolt holes etc. and that nothing really changed till the alluminum heads came out , i do not have anything but a set of iron 3.1 heads so i cant confirm my question myself, will the 2.8 3.1 and 3.4 exhaust manifolds interchange? will my 3.1 headers fit on the 3.4 heads? i found a good deal on a 3.4 block and id rather rebuild that then get a 3.1 reman for the supercharger project. thank you for your time guys.

 

My headers are on 3.4 heads.

Bolt patterns are the same, however all the manifolds are slightly different. Smog ports, heat shields, o2 sensors are the main things.

 

if you mean the intake manifold between the cylinder heads its ok since my supercharger has its own intake manifold, but im very happy they will bolt up. figured the 3.4 headers just got designed different because of body compartment space, so starting with a 3.4 instead of a 3.1 gives 20 more hp and trq to start with, add the headers and a homemade true duel exhaust (im cutting up the pacesetter y pipe to achieve the starting point) system, that should allow those gases to escape easily and let this system breath, what do you think that exhaust on a non sc system would add as far as hp goes? So now since it looks like im going with a 3.4 will a 3.1 performance cam work in this or do they make 3.4 performance cams? whats a good cam to use? i want to have a longer intake duration to take more advantage of the sc

 

Since you wont be using the SFI triggers off the cam, any cam that you could put in the 3.1, will go in the 3.4.

Yes/No, the exhaust manifolds on the 2.8/3.1/3.4 are different, as well as the base intake manifolds on all 3 are different as well.


Honestly, 90% of the stuff will cross bolt. Its just depending on if that other part has the correct holes for sensors, pvc, vac ports, etc.


Remember that the 3.4 has 9.5 compression, which is advised to be dropped if your boosting the engine. Also, that 3.4 will have 2 sensors in the block that you wont need. One on the pass side down by the oil pain, it can be removed and plugged with a 3/4" freeze plug. The other is the cam sensor front/top/center infront of the intake. I couldnt get mine out, but I'm sure it could be removed and plugged with a freeze plug as well.

 

how would you drop the compression? different cam and pistons? it might just be easier to buy the reman 3.1, i got so much stuff to worry about already, i need a little angel on my shouldar thats a fountain of knowledge to guide me

 

custom pistons

 

well that sucks, im going with a 3.1 for the simplicity, i dont care about top speed i just wanna get going fast so an extra 20hp wont matter much anyway but aw now im sad, lol