the factory had 1.73 stamped stud mount. i just got 1.73 roller rockers with guide plates. they are the small compression chamber heads and have been ported. they doo have the lock allen nut on the inside. i was told by another person to tighten to zero lash and then a 1/2 turn. going to go without a valley pan since the wiend people said it was not needed.
thanks for all the help.
JIM