Rebuilding the 289
3rd Gear Member
Joined: Feb 2007
Posts: 551
RE: Rebuilding the 289
ORIGINAL: my77stang
yup, basically, if your stock rockers have "lips" where it hits the valve its the rocker arms that center everything up and you'll need guideplates when going with roller tips.
if your stock rockers are smooth where it rides on the valve with no lip on each side to keep the valve centered, then the guideplates are built into the head and your ok.
if thats confusing or doesnt make sense - check the pushrod holes in the head. they are either oblong and wont let the pushrod move side to side or they are circles and the pushrod can flop all around in there. oblong = your fine. circle = you need guideplates.
btw, if your using stuffer springs and a higher lift cam you should be using screw in studs too. pressed studs like to pull out if you have higher spring pressure and that'll give ya a bad day
If your 289 and heads arethe original 1965 you will not need guide plates. The later 289/302 heads used rail guided rockers and have a larger hole for the pushrod. Those require guides when changing rockers.
if your stock rockers are smooth where it rides on the valve with no lip on each side to keep the valve centered, then the guideplates are built into the head and your ok.
if thats confusing or doesnt make sense - check the pushrod holes in the head. they are either oblong and wont let the pushrod move side to side or they are circles and the pushrod can flop all around in there. oblong = your fine. circle = you need guideplates.
btw, if your using stuffer springs and a higher lift cam you should be using screw in studs too. pressed studs like to pull out if you have higher spring pressure and that'll give ya a bad day
6th Gear Member
Joined: Dec 2006
Posts: 8,007
From: Citrus County, FL
RE: Rebuilding the 289
pinning always scared me, i have seen snapped studs that were pinned. never saw any screw in studs pinned though, never even heard of that.[&:]
what do i know? look at my sig [:@]
what do i know? look at my sig [:@]
2nd Gear Member
Joined: Feb 2007
Posts: 296
RE: Rebuilding the 289
yeah screw in studs are pretty much the standard that yousee, but .456 lift?whats your duration on that cam...but what i see alot of guys do is install pushrods without length checking...i mean trust me ive seen plenty of people get sent the wrong cam grind, pushrods for a chevy, order 350 # valve springs and get like 500# that are only good in race cars with a ton of lift and they get valve float or destroy a cam lobe or somethingand i have to rebuild there whole valve train...remember always degree your new cam, check pushrod length, make sure your rockers are the correct ratio if you ordered new ones, if you are increasing cam lift or durationa fair bit over stockcheck valve to piston clearence, and if running new valve springs check the valve springs to make sure they are not to soft or stiff and if they are double valve springs break in on the outer valve springs...
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