Pushrod Length?

Originally Posted by 289nate

You can just remove the guide plate and tighten the stud back down.

Haven't seen so many posts in a row by dfree that don't give me one single reason to disagree with him. LOL!

Jim, how old do I have to be to get one of those shirts? I feel more like an old fart every day!

Yeah, I guess I could do that. I actually mentioned that last night. The guy I'm working with can be stubborn sometimes. He didn't want to take the guide plates off. Anyway, I'll ask about it again tomorrow night, but I think he's just going to try the 302 pushrods he has, and check everything out with the dykem. Our assumption is that the 289 rods are too short, and that the 302's should be just about right. If anyone's interested, I'll repost how it goes.

OK- Here goes- once again I have no experience with what I talking about. The reason I said turn it around is because I thought that if you removed it, the stud would thread to a different depth, rendering a pushrod measurement that was less than accurate. Not so?

Originally Posted by ralphwiggim

Yeah, I guess I could do that. I actually mentioned that last night. The guy I'm working with can be stubborn sometimes. He didn't want to take the guide plates off. Anyway, I'll ask about it again tomorrow night, but I think he's just going to try the 302 pushrods he has, and check everything out with the dykem. Our assumption is that the 289 rods are too short, and that the 302's should be just about right. If anyone's interested, I'll repost how it goes.

Stubborn or confused? He'd rather grind on the checker than remove and reinstall two bolts?

289 and 302 stock length flat tappet pushrods should be the same length. Roller 302/5.0L pushrods are shorter at 6.25" I believe. Just don't want anyone to get confused.

Originally Posted by doug351

OK- Here goes- once again I have no experience with what I talking about. The reason I said turn it around is because I thought that if you removed it, the stud would thread to a different depth, rendering a pushrod measurement that was less than accurate. Not so?

A rocker stud doesn't determine how high the rocker sits. The pushrod and the installed height of the valve are what keeps it floating (for lack of a better term) at a certain spot. You would only be changing how many threads the nut will engage to hold the rocker in it's position by removing the guide plate. Throw a washer under the stud to make up for the guide plate if it bothers you.

THANK YOU THANK YOU THANK YOU! 289nate: I am trying to learn all I can through these forums, (which are an excellent way to further your automotive knowledge), but my first priority is to gather the necessary information to build my motor with as much insight as possible. So my learning curve is biased towards those things that directly relate to my circumstance, then to other applications, and finally, I'll spend some time trying to relate a piece of my limited knowledge here or there to help the occasional pathetic soul who knows less than me....-(no offense intented to anyone whom I may have tried to help.) So, sometimes , either you get it or you don't. I wasn't. Funny how just a few of the right words can turn the light on, and bring a hopelessly lost soul into the light. I really hadn't pictured in my head how the adjustable stud geometry worked, since my focus has been on pedestal mount rockers, and the fact that to run studs and pushrod plates on heads that came with them requires machining the rocker bosses for clearance, but the original geometry is a bolt-down , non adjustable system, kinda mixed up in my head and I forgot the stud mount system is adjustable. It sounds stupid, but the fact that those bosses that determine the fixed height of the bolt-down pedestal rockers had to be clearanced to allow the addition of push rod guide plates or studs somehow incorrectly imprinted in the back of my mind that the bolt head that seperates the top and bottom of the stud determines the height of the rocker , like in a bolt down system. Now that you have brought me into the light , there is no reason to reinstall the pushrod guide plate-(the installed valve height determines one side of the equation), what you are looking for now is a pushrod on the other side that puts you centered on the valve stem tip throughout the valve cycle. Man, I feel almost as stupid as that guy that won't pull a guide plate. Maybe he had pedestal heads that had to be machined for guide plates and thinks that they won't go back the same if you pull them. Nothing else makes any sense.

Originally Posted by 289nate

289 and 302 stock length flat tappet pushrods should be the same length. Roller 302/5.0L pushrods are shorter at 6.25" I believe. Just don't want anyone to get confused.

There are a few different pushrod lengths due to changes in valve stem lengths and different rocker types..The rail vs non rail rocker setups as well as the pedestal style...My Tom Monroe book lists these lengths for the 221-302.

1962-69 1/2---6.825
1969-77-------6.905
1977-78-------6.883

Originally Posted by frdnut

There are a few different pushrod lengths due to changes in valve stem lengths and different rocker types..The rail vs non rail rocker setups as well as the pedestal style...My Tom Monroe book lists these lengths for the 221-302.

1962-69 1/2---6.825
1969-77-------6.905
1977-78-------6.883

Good to know. Thanks!

Originally Posted by 289nate

Haven't seen so many posts in a row by dfree that don't give me one single reason to disagree with him. LOL!

You and me both lol.

Nice work Dfree383 =D

Cris

Lol

Just to add....

I have a 306 with 3/8" screw in studs, guideplates, +0.100 valve tips, 1.85 double springs, Miller 1.7 roller rockers, Isky 280 MegaCam, and Speed Pro lifters. When I measured....

7.100 inches is what I need at MID-LIFT. It is critical to measure at the MID-LIFT point.

Moral of story, as mentioned many times, EVERY combination is different.

Measure to get the correct length.