i just bought some comp cams magnum rockers (the roller tip ones, 1.52 ratio) and am going to put them in my 283. it says in the instructions and i have read in afew other places i need to use guideplates with these rockers. how are these guideplates installed? can it be done with the heads on the motor and just the valve covers removed? i REALLY dont want to have to pull the heads for this. also, since im not changing the ratio (the stock ones are 1.52's too i believe), am i going to have to use different length pushrods when doing the swap? thanks alot.
smlblcks10
guide plates
The guide plates are mounted under the rocker studs. You need to have screw in studs. Remove the studs. Insert guide plates. Put sealer on the stud threads as they screw into the water jacket. Torque to about 40 ft lbs. Install push rods and lifters. Check the location of the roller tips. They should sit on the center of the valve ends. Rotate motor to make sure none of the pushrods are scraping on the head casting. To adjust for push rod scraping or tip location. Loosen rocker studs and move guide plate. Retorque rocker stud.
The guide plates are mounted under the rocker studs. You need to have screw in studs. Remove the studs. Insert guide plates. Put sealer on the stud threads as they screw into the water jacket. Torque to about 40 ft lbs. Install push rods and lifters. Check the location of the roller tips. They should sit on the center of the valve ends. Rotate motor to make sure none of the pushrods are scraping on the head casting. To adjust for push rod scraping or tip location. Loosen rocker studs and move guide plate. Retorque rocker stud.
yeah i keep getting mixed opinions on wether i need them. the comp cams instructions that came with them said i do."part #'s 1412 & 1416 must be used with pushrod guide plates to maintain proper rocker arm alignment". thats straight from the manual. the part number on the side of the box says 1412-16, so basically theyre telling me i need them. The manual also says part #1417 &1418 do not use pushrod guide plates and are self aligning, but i was under the impression that thse were for the newer style v8's. (btw, the swap is being done on a pair of 1.94 heads off a '69 vette). can i just swap the ones i have for some self aligning ones and be done with it or will thsoe only work on the newer heads? im not doubting your advice whatsoever coldknock, but since the manual and a couple other people tell me that they should be used i cant help but wonder. these are expensive for a kid working minimum wage so i want to be absolutely positive i do it right the first time. if a couple people can completely assure me that i dont need them then i'll go ahead and do it without but like i said, i want to be sure. so to recap, these are the comp magnum roller tip rockers, 1.52 ratio (same ratio as what is in there) and are being swapped into a set of 1.94 heads from '69 whcih are, to my knowledge, otherwise stock. do i need the guideplates or not?
p.s. i know i asked this question a little while ago and i hate to beat this to death but once again, opinions were somewhat mixed and i want to be sure.
if someone could explain exactly what guideplates do and why they are needed in certain cases it may help me understand a little more and would also be greatly appreciated. thanks alot
p.s. i know i asked this question a little while ago and i hate to beat this to death but once again, opinions were somewhat mixed and i want to be sure.
if someone could explain exactly what guideplates do and why they are needed in certain cases it may help me understand a little more and would also be greatly appreciated. thanks alot
No problem dude, I'd want to be sure of anything I was doing too.
Below is a picture of the guide plate on a Trick Flow Twisted Wedge head. See how the pushrod hole is round and much wider than the pushrod itself? There's nothing to support the pushrod so it needs the guide plate to do the alignment.
![Image]()
Here's a picture of the factory pushrod slot in an old GM head. See how it has a slight oval shape. The flat sides of the slot support the pushrod and keep the rocker in alignment with the valve stem tip.
![Image]()
Also, don't use guideplates on factory GM heads unless you widen the pushrod slot. It will cause the pushrod to bind, bend and/or break. The guide plate and the factory slot will almost always be out of alignment by a few thousandths and rub the pushrod into submission.
Now for the rocker arms you mentioned. The rocker arms you mentioned that do not need guide plates, self aligning they're called. These are later model designs used because later model heads, like Vortec heads, don't have the oval shaped pushrod slots or guide plates. The stamped style factory rocker arms, like these in the picture below, drop over the sides of the valve stem tip. This allows the rocker arms to do the aligning themselves.
![Image]()
The aftermarket roller rocker designed for these applications have small "washers" in each side of the roller tip to keep the rocker in alignment with the valve stem tip. Here's a picture of a self-aligning roller rocker.
![Image]()
Regular rocker arms do not have these "washers". Here's a picture.
![Image]()
Do not attempt to use these self-aligning rocker arms on old style heads. The "washers" that keep them aligned with the valve stem tip will interfere with the valvespring retainer and lock and will make very bad, very expensive things happen. Just like using guide plates on factory heads without widening the pushrod slots, which is kind of like poking a hole in something just so you can spend money to fix it.
I hope that I helped to make this a bit clearer for you.
Larry
Below is a picture of the guide plate on a Trick Flow Twisted Wedge head. See how the pushrod hole is round and much wider than the pushrod itself? There's nothing to support the pushrod so it needs the guide plate to do the alignment.
Here's a picture of the factory pushrod slot in an old GM head. See how it has a slight oval shape. The flat sides of the slot support the pushrod and keep the rocker in alignment with the valve stem tip.
Also, don't use guideplates on factory GM heads unless you widen the pushrod slot. It will cause the pushrod to bind, bend and/or break. The guide plate and the factory slot will almost always be out of alignment by a few thousandths and rub the pushrod into submission.
Now for the rocker arms you mentioned. The rocker arms you mentioned that do not need guide plates, self aligning they're called. These are later model designs used because later model heads, like Vortec heads, don't have the oval shaped pushrod slots or guide plates. The stamped style factory rocker arms, like these in the picture below, drop over the sides of the valve stem tip. This allows the rocker arms to do the aligning themselves.
The aftermarket roller rocker designed for these applications have small "washers" in each side of the roller tip to keep the rocker in alignment with the valve stem tip. Here's a picture of a self-aligning roller rocker.
Regular rocker arms do not have these "washers". Here's a picture.
Do not attempt to use these self-aligning rocker arms on old style heads. The "washers" that keep them aligned with the valve stem tip will interfere with the valvespring retainer and lock and will make very bad, very expensive things happen. Just like using guide plates on factory heads without widening the pushrod slots, which is kind of like poking a hole in something just so you can spend money to fix it.
I hope that I helped to make this a bit clearer for you.
Larry
rockers
Look at the last post larry (coldknock) made. He spent some time on this and it is a really good explanation of what is going on.... stop talking to all the different people they are just going to keep confusing you. The guys on here know there stuff.... The only thing i would add is that if you look at the picture of the stock heads you will see the slots are the guide plates. So what the instructions are telling you, but maybe not in a good way is. You need something to guide the rockers. That can be the heads (if they have the stock rocker guides) or guide plates....
Keith
Look at the last post larry (coldknock) made. He spent some time on this and it is a really good explanation of what is going on.... stop talking to all the different people they are just going to keep confusing you. The guys on here know there stuff.... The only thing i would add is that if you look at the picture of the stock heads you will see the slots are the guide plates. So what the instructions are telling you, but maybe not in a good way is. You need something to guide the rockers. That can be the heads (if they have the stock rocker guides) or guide plates....
Keith
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