need a bit of help...

so i have a 1969 dart gt 273/904 that i want to beef up...

first- off how do i identify my rear end..i counted 10 bolts..ive been told its not a 8.75 which i beleive because it doesnt look very beefy....

second- i want to work with what i have,im on a budget...i want to remove and install 3.55 gears and make it posi is this even possible with what i have??

third- i just picked up a bad *** set of wheel's (small bolt pattern 4'')if im forced to buy a 8.75 rear end can i put my axels on so i can use these wheels??

thanks alot i want to make it a decent street machine but not sure what i can use:icon_smi: