Stick with the lightweight push rods and blueprint the rockers if you are chasing added performance from them. Mods like offset bushes to alter the rocker ratio. Radise the areas where the castings merge at abrupt angles etc. Even reduce the contact pad to the size that is in contact with the valve stem. Mods to the rocker shaft should be undertaken at the same time. I think $600 spent on the head itself [valve and port mods etc] would net more power.

Yeah thought as much.. the ute is mainly going to be a street car (weekender) but track time on some of the weekends and some hill climb events at Canberra or wake-field because they are close by...

So it could come in handy with some hill-climb but at the same time it wouldn't be worth the cash and extra parts for a weekend one a month

You will need different push rods. ball at both ends type, unlike the factory ball and cup type. With the rocker ratio of 1.5:1 , [factory rockers are 1.43:1. extra attention will need to be taken with valve to piston clearance. The extra lift can also affect the clearance needed for the valve spring retainer hitting the valve guide / stem seal and also valve spring coil binding.

What are you wanting to achieve with the engine. If its a streeter I would invest the $600 elsewhere in the build.

Just curious guys im going to be doing the camshaft on the ute (a15) soon and in doing so it will of course ill upgrade to double valve springs, new light weight push rods and the 312-7.5 camshaft, lifters valves the works..

But what my main question is, is anyone using or have used the Yella Terra YT6023 and is it a high ratio rocker arm?? (A15)

Is it an easy install with out further parts needed and will the normal parts themselves such as the pushrods and the valve spring seats sit correctly with this rocker arm?? or is it better off to just use the normal rocker arm..

I have attempted to find more info on the arm itself but i can't find alot about it even on yella terra itself...
http://www.yellaterra.com.au/products ... entity=4&modelIdentity=24

That and is it really worth the $600.00 for it??

http://www.yellaterra.com.au/products ... productCategoryIdentity=4

http://www.ebay.com/itm/Nissan-Datsun ... er-Arms-Set-/330875886899