Jester

I'm picking up a set used, but I just have standard stock 90 self aligning stockers. Will I need guide plates? what happens if I run without them?

Engineboy

Chevy used 2 styles of rockers.

The older heads had guides built into the head and didn't require self-aligning rockers. The pushrods kept everything aligned on the holes in the heads.


The newer heads went to bigger pushrod holes in the heads and used self-aligning rockers.

You need something to keep the valvetrain in line and not slide off the top of the valves (ask me how I know )

So yes, if the H.S. rockers are NOT self-aligning and you have self-aligning on there then you need to have the heads machined for guide plates.

Unless you were planning on pulling your heads, I personally would get self-aligning rollers.


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ASE Mechanic/Machinist/Smog Tech

RTKTGTR 1999 NBM T/A, flowmaster,FRA,Pro Kit,BMR STB, polished calipers.
1986 Chevy 3/4 ton pick up,flowmasters,4.10s,
1981 corvette FOR SALE
1995 ZX6R,Yosh,D207s

GO #3

Pablo

iTrader: (1)

a funny thing i noticed about your heads (and mine) that the holes drilled for the pushrods are actually the same size as those in heads for non self aligning rockers
The rockers on my 87 t/a were non self aligning and the heads were #187s which were the same heads on my 89 which had self aligning
so check out how much side play you have in your pushrods i think you can use the non self aligning on the 187 heads

RichS

You can use non-self aligning rockers on any head up to 96(non sure of after 96) as long as you use guid plates and hardened pushrods. I used the Harland rockers on my 383. They are a good quality rocker.

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95 Corvette
Morgantini Racing heads,ported intake,Dynomax mufflers, Vortex Rammer,1.6 Roller Rockers,
Holley 52mm TB, Line lock, 4:10 gears, Nitto DRs
Collector Edition wheels
PA Plate "4U2WANT"

Jester

I noticed the same thing on mine...thats pretty much why I'm asking instead of just assuming I need guidplates.

dan

You need guide plates, and hardened pushrods meant for guid plates. Unless you like breaking stuff.

Formula-91

Been there, done that. My heads have the pressed in studs, so no guideplates. I put a set of non self-aligning 1.6 rockers on. One week later the number three intake rocker twisted sideways, compressed the valve spring enough to pop out the keepers, and drop the valve. The only thing that saved me was the valve seal, which kept the valve from dropping all the way down. Live and learn...

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91 Firebird Formula. Converted to carb. Holley 750. Forged Flat top pistons. 10.5 to 1 compression. ZZ-9 Cam. Ported L98 Heads.
150 shot NOS, 700r4 w/ 3000 rpm converter and 3.73s in the back. Headers w/ full dual exhaust. 27.5 inch McCrearys. (free slicks)
12.98 @ 106 Natural,
11.83 @ 113 NOS.

Jester

uh...huh. that answers that..thanks guys