yeah LT1 installed height is 1.8. if you ran them theyd bind before you had the lifters all the way up. id have to go threw the specs again. looks like .650 ID and 1.25-1.310 OD MAY require machining depending on heads. Lt1 springs wont even fit your pockets! haha So yeah get the 918's as a kit. the hat will change the installed height.
http://www.compperformancegroupstore..._Code=26918-16