Yes i know its been mentioned before but the treads are old so anyway.. I'm thinking of putting a 3kc head on 4kc is it only the Bigport head which increases performance or any head?

 

The port Size on the 3K head I'm looking at is 25mm ish I'm guessing its not a bigport? will this have much of a power increase?

 

An will this be worth the $80 i'd be paying for the head?

 

Cheers (:

putting a 3k head on a 4k motor increases compression so why not shave down the 4kc head?

 

3k is older and welsh plugs seam to give people problems

It could well increase the compression a little too much depending on what's been done to the head. Plus the ports are tiny. I think the 4k ones are generally bigger, or you could port it.

 

Go with Evan's suggestion.