is true that difference between GSR and regular integs engines is realy just the head

 

No, compression ratio is lower due to different piston design such as that on the ls.
If the bottom ends were all the same then an LS vtec would be the same as a gsr (basically)

 

also the gsr motor has slightly lower displacement and slight better r/s ratio

 

Please ask him why and let us know. The word "better" is really vague. Is he inferring that the GSR head will give you "better" gas milage than the Type R head? Or just all around better? More HorsePower = BETTER in my opinion and according to honda, the Teg Type R head produces 205hp @ 8000rpm whle the Civic Type R still pumps out 185 HP with only 1.6l's of displacement. Let us know.

 

Don't forget that non-VTEC blocks don't have oil squirters and oil passages for them cast into the block.