340 J heads on a 318?

I have been doing a lot of reading about heads, and most of it seems to be related to 360 J heads on a 318 is a bad idea because Of lack of compression, and that "302" swirl port heads were the way to go.
I did however find someone selling 340 J Heads (202/160). would that be the same issue as the 360 heads?

Any thoughts? Thanks!
Author: admin