Heads

[JOSEPHOUYSON]

I have some other cazy idea that my acualy be stupid. Well, apparently the 4.0 is similar to the 2.9 litre (the 4.0 is basicaly a 2.9 stroked and bored). Since this is the case will 2.9 litre heads bolt on to a 4.0, are the heads identical? Because World Products makes a performance 2.9 litre head, I dont know If this would work on a 4.0. If this is a possibility then I will look into it because I have seen what world products heads do for my dads 351w in a 1 ton crewcab 4x4, those heads kicked butt. If anyone knows if the World 2.9 litre heads from world would benifite a 4.0, or even bolt up to it, please let me know.

 

[jimbo74]

i doubt the sizes are the same internally...which means it would have a huge compression ratio and that isnt a good thing on a daily driver...... check out vanir technologies for some phat performance parts...

 

[MSTNGGUY88]

If that's all the motor is is a bored stroked 2.9 then they should work. Try to find out what size the combustion chambers are on both heads so you can see if your compression will go to high. I'm sure World Products can tell you if they will work.

 

[Raceit]

Not sure if this will help, but here is a link that has some good info on the 4.0L block and heads. It's a bit of reading, but one thing to note is that there was about 3 different 4.0L blocks and about 3 different head designs though out the 4.0L history. It's said that if you combine the wrong combination of heads and block you may cause the dreaded knock that pleages many 4.0L's.

Dead Link Removed