3.9 Rover / 4.0 heads, any negatives regarding stock EFI?

[tdecell]

I've got a 1989 Rover 3.9 to go in my BGT, it's a 8.3:1 CR engine. I've read that 4.0 heads will increase compression ratio just a bit. I don't want to go too high,(don't really want to have to use premium fuel if I don't have to).  I'm planning on using the factory 14cux EFI. Would raising the CR have any negative effects on the way the EFI operates? I was going to stay with a stock engine, but have come across a set of 4.0 heads for about $100 and am thinking about picking them up this weekend. Thoughts??

[Moderator]

You have to keep in mind that 8.3:1 is a very, very low starting point.

[tdecell]

That's why I wanted to go to the 4.0 heads... Get that pushed up a little bit Curtis.