Makaveli

i confused myslef once again. i know if you dont have self aligning rocker arms, then you need guideplates, hardened pushrods, and screw in studs.

do you need to machine your heads to have guideplates or can they be installed on a stock head?

now wat if u have a flat tappet cam in an older block, can you use self aligning rocker arms in the first place instead of having to add guideplates/hardened pushrods/screw in studs? or does the head have to be a later style to use self aligning rockers?

will they bolt up and work to a stock pre-87 head?


thanks for the help :lala:

ede

it confuses me too, but it doesn't take much. basically you have either SA or non SA. the non SA are located by guide plates or holes in the head, the SAs use neither, you also can't use both, say guide plates and SA rockers. you can switch non sa to SA or SA to non SA provided you use the correct parts. to use guide plates and screw in studs you need to take around .4 off the stud boss and tap the holes. no idea what it cost ,i do my own. i will tell you it takes several hours so figure 2 hours of shop labor.

RB83L69

You need one, and only one, of three available systems to hold the rocker on the valve stem: "self-aligning" rockers; or guide slots in the heads where the push rods go through (that's what Chevy small blocks all had stock before SA rockers); or guide plates. If you have none of these 3 things, the rockers will not stay on the valves. If you have more than one, something will bind, and usually some part or other will be rapidly destroyed.

You do not have to have all that stuff to use non-SA rockers, IF your heads have guide slots like all factory heads did before 87. In no case are hardened push rods "required", although using good quality parts is always a good idea; lots of motors (including all big block Chevys, for example) use the same crap push rods as what comes in our motors, with guide plates, and they run for hundreds of thousands of miles.

if you have stock heads, machine work is necessary in order to istall guide plates. They are retained by screw-in studs. The top of the stud bosses has to be fairly accurate and straight unlike the as-cast situation the factory leaves with the pull-out studs.

None of this has anything whatsoever to do with roller cams or roller rockers. You can run a roller cam with any of the 3 retention systems, roller rockers with any of the three or with either flat tappet or roller cams, etc.

Self-aligning rockers will bolt up and work on a pre-87 head, IF AND ONLY IF you do not use guide plates, AND you have the push rod slots enlarged to where they no longer attempt to guide the push rods.

Makaveli

aahh thanks for clearing that up... nice n simple :-D i thought you had to do more to use self aligning rockers on an older factory head, so i get it now. oohh one more question:

when looking for rockers, i always see 3/8" stud next to it... sometimes 7/16, but mostly 3/8"... does the factory come with 3/8" studs?

the search button is unreal hehe i read in a post that the factory is 3/8" on the newer blocks.. wat about the older ones? still the same i would suppose?

RB83L69

Right, 3/8" is factory on all of them.

ede

if you buy screw in studs you'd want 7/16-3/8 that is 7/16ths on the bottom since the 3/8ths hole you have will work out good to tap it to 7/16ths and then you'd want 3/8ths on the top half of the stud to work with stock or aftermarket replacment parts.

evil t/a

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I dont agree with that , I have personlay seen a 350 using Sportsman 2 heads gouge a stock set of pushrods and 16 new non hardened PAW pushrods within a week of each other . Comp cams hardened pushrods fixed the problem. If the head manufacturer calls for hardedned pushrods then just spend the 29.95 to get them. More than a few people have had issue using non hardened pushrods with guideplates.