effective compression ratio?

This isnt for a maverick but could apply to one. My buddy has a gmc syclone that has a bad engine and was wondering if he could run a stock na 4.3 with 9.0 cr on 11.5 psi which would be the same effective cr as the stock engine with 8.3 cr on 14.5 psi. I'm thinking it will be ok but not sure?

 

My Buick GN motor has a static 9.0:1 CR and I can run 23 PSI on 93 octane and alky. My pistons are forged, but his stockers would prolly do OK as long as there was no knock.

 

Not really related but my motor is 9.1 or so and run 20+psi on 93 with cast pistons and alky

 

Also would the truck need a retune just from changing the compression ratio? Plan is to throw it in there drive it on low boost until has the money to rebuild the stock motor

 

Shouldn't be enough difference to merit a re-tune...