i have a question on a 302 with 289 heads,im having the heads built with 1.94 int.,160 ex.,milled .20,how much cam can i put in it without hitting the pistons?,it has flat tops

 

What is the purpose of the 289 heads on a 302? I ask because when I bought my car it came with a fresh 302 and they guy wanted to point out that it has 289 heads. I know they fit and work, but is there a reason other than they were available? Not trying to hi-jack, but curious .......

 

I don't have my "Ford Interchange" book with me, but I think the 289 heads provide a little more compression, by virtue of slightly smaller chambers.

 

the early 289 heads have a 54cc chambers,more compression,

 

Yes, smaller chambers.