Gt40p Pushrod Question 500/510

[TRIBUNAL]

So I am finishing up my engine and looks like I got a tiny bit of rust on a few of the pushrods, so I may as well replace them.
Now I spoke to summit tech and he suggested that I may need a different size depending on the cam. The cam is a Lunati 20350514 500/510 lift.
I was thinking of reusing the stock rockers and upgrading down the road to 1.6 rollers.
The guy at summit said I need to measure.. something....
I don't know if this is something that can be answered by just having the specs or if it's something I need to measure myself.
I'm just looking for some advice here, thanks guys.

 

[TRIBUNAL]

bump

 

[General karthief]

If you have the stock push rods try installing them and see if they adjust ok, I don't know anything about that cam, let me get another opinion
@a91what @madmike1157

 

[SlayAllTires]

This may help.
http://www.hotrod.com/articles/setting-pushrod-length/

 

[a91what]

Nope, buy a pushed length check tool and order the right ones the first time.

 

[CarMichael Angelo]

He wanted you to measure P to V.
He wants you to check for piston to valve clearance.

The camshaft, whether it be the stock one that came in the engine, or an aftermarket unit doesn't dictate the need for a different pushrod.
In other words, if all you did was change out the cam and upgraded the springs,...nothing changes. Only after you take the steps to really upgrade things, does that need even arise.
Increasing spring rate may require a better pushrod, but it should still be the same length as the stocker was that it replaced. Typically,..a better pushrod means a chromoly or hardened steel piece,..a larger diameter, or maybe one that was built as one piece w/o the usual ball ends pressed onto the shaft of the pushrod.

Only after you start changing things beyond that will you have to go through the steps to measure pushrod length. Milling the heads, changing the head gaskets for a thicker/thinner unit, Different heads w/ roller rockers, the use of guide plates,..all require that you either check the length of the pushrod, upgrade it's diameter, change the length, or change it to a hardened unit because of potential wear related side issues.

Not just because you changed the cam.

Checking P to V clearance is a much more involved process. It can be done with the head on as is, but you'll need a lot more experience than you currently have to do that. Read here:http://www.hotrod.com/articles/hrdp-1303-checking-piston-to-valve-clearance/

 

[TRIBUNAL]

Thanks a lot for the help.
The heads did a slight mill just to even them out. i believe 010
is that enough to be concerned?

If so does anyone recommend what tool to buy. I saw a video by late model resto that showed a method of measuring using a tool. Then I saw a tool on late models site that included a special lifter, do you need the special lifter kit or just the basic tool?

 

[Mustang5L5]

If oyu have a spare lifter kicking around, you can make it solid

https://www.stangnet.com/mustang-fo...id-lifter-for-checking-pushrod-length.758168/

 

[TRIBUNAL]

I do have lots of extras. I guess I will try that.
So I can use that with a stock pushrod at zero lash and measure the mark it makes like they discuss in the video guide on late model resto?
ty for the help,