gtu/gxl? whitch one? nobe

[workmank]

this may sound like a stupid question but this is my first rx-7 and i just dont know yet but i bought a 90 rx7 on the title it says rx7 gtu/gxl. i would assume there is a difference right and if so how do you tell? i also have another question i have two complete engine w/trany sets both 13b's. one that was in the car with a 351 ecu the other i beliave is a 326 ecu. the one with the 326 ecu has a different intake front cover and center side housing. the one with the 326 ecu is out of a 86 rx. what i am really getting at is are the front covers and intakes inter changeable i once again would assume they would be the rotary housings and all but the center surface look identical. i would just like to make sure. the one out of the 86 has what looks to be a egr valve in the top of the center surface right below the intake correct me if i am wrong. but the one out of the 90 has a similar place but no holes i know its not a block off plate it just doesnt have it. which intake would be best for power cause they are both different the intake out of the 86 is longer and seems to requare a different wiring harness. thanks for the help ans sorry for the long post and so many questions in one post. again thanks. looking forward to hearing any input anyone has to offer.