lifter pre-load question

[meangreen93]

hello everyone I almost finished with my 302 buildup (1993 mustang coupe 302 HO automatic AOD) its a stock bottom end with an F303 cam, stock heads with port work, stock valves with 5 angle grind, stock lifters and pushrods, and 610 maximum lift springs matched to the cam. I bought a brand new set of Scorpion 1.6 roller rockers and have them installed and this is where I am stuck.
should I install them with shims? do I need a longer pushrod? how do I determine what pre-load I need?

 

[65ShelbyClone]

You just tighten the rocker bolt gently unto you get drag on the pushrod, then tighten it with a wrench you should have to tighten it ~1/4 to 3/4 turn before the rocker pedestal bottoms. If its less than that, you need a longer pushrod. If its more, you need shims. I wouldnt expect you to need new pushrods with your parts, though.

 

[v8only]

don't forget to be on the base lobe of the cam when you do this.