Michelob

I've got some D-port ZZ-4 heads( from a 90 vette ) going on an 87 L-98 and also will be adding a 94 Lt-1 cam out of a trans-am. can i go for a straight bolt on with some 1.6 roller tip rockers to this setup?? None of the online catalogs say whether the roller tips are self-aligning or not.
I'm guessing I need self-aligning but am not sure.
also can i use the stock 87 L-98 pushrods??
Do i need to remove the guideplates ??

Any advice would be appreciated.

DannyT

If you have guideplates you don't need self-aligning roller rockers

Michelob

from my understanding the guideplates on the vette heads fromm 88 on were no longer hardened and only there to hold the pushrods in place for assembly. So the rockers were self-aligning from 88 on. Any comments on this??

Todds1987iroc

I have '88 vette heads on my 305 and they had guide plates that are worthless. After about 100 miles one of the rocker arms slid off the center on the valve, bent the push rod and wore a big gouge in the guide plate. (no other damage ) You need to use self-aligning rocker arms with these heads.

Michelob

thanks for the input. Think i have it sorted now. found Comp cams self-aligning roller tips which will work for my setup.

89Formula350WS6

CAT makes some self-aligning 1.6:1 roller tipped rocker arms that look alot like Comps but are almost 1/3 of the cost. They seem to be working out good so far.

Guest

Personally, I would run guideplates (you just have to take the stock studs out, and install the guideplates) and run non self aligning rockers.

89Formula350WS6

I know this thread is about the aluminum Vette / ZZ4 heads, but I still have the stock cast iron L98's on my car, so I had to stay Self-aligning.

mhaskell

I have a stock 350tpi l-98 with just intake/exhaust done. Do you have a part number or description of a roller tip rocker that would work on my motor with having to modify anything? Cheaper is better. I would like to run a larger ratio for a bit more duration instead of putting in a new cam. Thanks for the help.

Guest

Iron heads? Self aligning rockers? Need to know.

mhaskell

I just picked up a set of these. I should get them on in a two weeks or so. I'll let you know how they work out.

http://cgi.ebay.com/ebaymotors/ws/eB...tem=1874114860

89Formula350WS6

Those are the same ones I have. I haven't installed them yet either, but they look like the quality is very good.

mrr23

iron heads i'm running 1.6 roller rockers non SA

www.fl-thirdgen.org/rockerswap.html

Guest

Depends on the year, as to what you should run. Theres L98's running around with non self aligners (87's), and newer ones that need the self aligners. Shouldnt use them on heads that dont need them though, that could cause problems.

mrr23

mine are 1989 heads and i'm not using the SA

Guest

And no guideplates either? Doesnt sound like a very wise idea to me. I sure hope those pushrod holes are slotted and not round.

mrr23

iron heads have no guideplates. and yes they are slotted. i've been doing this for a little while. so long as the holes are slotted, then non SA will work. if the holes are round then SA are required. the whole SA thing is such a farce. it's nothing more than redundancy because GM made such crappy rocker arms to begin with. yes, i have read the posts where people have switched from SA to non-SA rockers and had problems. something else is wrong. maybe rocker not adjusted properly. stud pulling out causing the rocker to come loose and fall off. i had the comp cams 1412-16 1.52 non-SA on since at least march 2002. until i put the 1.6 full roller rockers on in sep 2002. no problems. but i will always remember a man named murphy. it works for me, but someone else here will try it and have a problem.

Guest

Well I've been doing this for a while too, in case you were thinking otherwise. You need some sort of pushrod control, but having 2 invites room for problems. I have personally witnessed the damage on other peoples cars. And I know most stock iron heads didnt come with guideplates, doesnt mean there arent any on now.

I know GM did use some slotted heads with SA rockers. Their SA rockers have tons of side-side play though. The aftermarket SA rockers I have seen have much tighter tolerances. Doesnt leave much room for error.

mrr23

nope. wasn't thinking otherwise. you are one of the respected elders here. yes you need pushrod control. my original 1986 5.0l motor out of this car had SA on them. heads were slotted. the 1989 motor i got these heads from had SA rockers on them also. but just not needed when you have the slotted holes. if the pushrod just barely fits into the slots, then SA not needed. the slotted holes in the head control the pushrod from moving around. the SA keep the rocker from moving around the valve tip. which happens when the flex in the middle. because they are nothing more than thin metal stamped in to existance.

Guest

I'd just like to add... I hate GM SA rockers.


Ferd's design aint any better. I ditched those off my Ferd a long time ago.

Your 86 had SA rockers on it huh? Weird. Someone had to have swapped those on at a later date. I've seen worse though, amazing what sorts of stuff people do to engines.

jmd

iTrader: (4)

Then the rockers were not original.

Matthew

89Formula350WS6

Since the SA rockers were on 87 models, maybe his 86 was a late production model. Sometimes new model changes are phased in during the end of the production run.

mrr23

sorry to disappoint you. but it was the original 5.0l 153k on it when i got it. car was all original right down to the crappy red interior. but hey i could be wrong. i'll check the old rockers tomorrow at work.

jmd

iTrader: (4)

I'll be honest, I just flat out think they're changed. The Iroc my TPI is out of had a #'s matching 5.0L block w/ the correct heads, and my 86 has the original engine w/ again non guided rockers.

153 raises suspicion to me. Not trying to be harsh.

Matthew

mrr23

like i said, i could be wrong. i'll check tomorrow.

mrr23

ok found my original rockers. they are the non SA design. my mistake on that one. will have some pics up shortly.

mrr23

going to post some pics. not the best. the middle one is a SA arm. the outer ones are non-SA. as you can see, the non-SA one on the left moved alot side to side. the one on the right barely moved at all. has the same wear pattern as the SA rocker. so, either the pushrod was bending side to side causing the rocker to move. or the rocker flexed more than the other one. causing it to shift to one side and the other. or rocker loose due to lifter collapsed, stud pulling up or nut backing off. i would believe one of the 1st two.

mrr23

next. the one on the right didn't wear in the middle either. it was to one side. this would indicate that the pushrod hole in the head wasn't where it needed to be. due to core shift making the head.

mrr23

finally, they made the SA arms to force the rocker to stay centered on the valve because the the core shift in the making of the heads. this made the pushrod not completely parallel with the stud.