thanks KaliMan....i ended up doing .035..what i didnt even think about was the fact that i could have just checked the gap of the old spark plugs..lol..oh well. got them all out, and then realized AutoZone gave me the wrong size oh well, its all taken care of now...now off to installing a WELDED Differential into the Nissan S13 (240sx) drifter style!
A piece of advice:
Never thrust on the old spark's gap, they might change their original gap for electrical wear or abrupt temp changes, so u did good not making that mistake.
By the way, that diff will run great, next step could b a hardened springs and stabilizers.
Take care and good luck.