Got my heads back from the machine shop. The lt4 rr's look like they clear the locks and retainers well! I have arp 3/8 screw in rocker studs. Should i put any thread locker on the threads? Should i measure for spring install height considering i dont know what it is? I told the napa machine shop to set them at 1.800 but have no paperwork to verify that they did it correctly. Im using pac 1218 springs good to .600 lift. The cam im using has .536 lift. Am i okay for avoiding coil bind?

 

Put thread sealer on the threads as most of them go into the water jacket. Actually some go into the intake runners. FWIW..

 

stock head spring height is 1.750. The machine shop would machine the spring pocket down slightly for a 1.800 installed spring height and use shims under the spring locator if necessary to get a 1.800 height. If the machine shop did not machine the spring seats down than the springs may be installed slightly shorter. With the cam lift you have no big deal IMHO as you have .600 max lift springs so you won't see coil bind. If your cam was .585 lift...you would be close if not at coil bind with the spring installed slightly shorter.

your seat and open spring pressure will be slightly more than spec but again no big deal with the over all combo.

If you want to know for sure you can use a spring height tool to measure what your springs are really at since the heads are off the car. Easier to work on.

On the ARP stud install, use "thread sealer" (generally the white stuff), not loc-tite. 50 Ft Lbs TQ

 

Thank you!! I may try and check spring height just for kicks.

 

Installed height really depends on the shims/locators/retainers (and sometimes locks) you use. For example, the installed height of the Crane 10308-1 kit on stock AL heads comes out to around 1.850-1.875.

You need a valve spring micrometer to really know. You can get a Proform tool on eBay for around $40-50.

And if your heads are unported then there's no need for thread sealer on rocker studs. All holes should be blind.

 

You can use a dial caliper, set it on the edge of the spring and measure to the bottom of the pocket. Then subtract the thickness of the spring seat.

 

HMMM, I just went and looked again and my iron heads are drilled all the way through to the intake runner,port matched only. From GM that way.

 

I read permatex #2 is a good thread sealer?

 

But those are iron heads with pressed in studs, you shouldn't be taking them out anyway unless someone paid to have screw-in installed.

And yeah, I like permatex #2. I use it on head and water pump bolts all the time.

 

I machined down the seats and tapped for screw-in studs,milled out the pushrod holes, enlarged the spring pockets, and turned down and shortened the valve stems to improve the lift capabilities. pushrod guides installed also. Rector Seal works good too.

 

Could i do thread sealant on the bottom threads and a dab of blue loctite on the top threads to prevent the studs from backing out? The best of both worlds?