Brad, you may be correct, I had the heads done in '98 and don't recall all the details of the work. However, as I mentioned, Crane made these dual springs to fit bone stock heads. They are 1.46" OD and one would need a seat/locator at least the same size or slightly larger. Heck, I think the .015" hardened shims Crane supplies are 1.50" OD. I don't think CNC would waste the time milling the seat pockets a measley extra .004" or something. So I think my pockets are oem size. I really believe that since a Crane spring with 1.046 OD fits the pocket then a 1.50" seat/locator could easily be made to fit. That is what I did.

I don't know anything about CC987 springs. I haven't considered those.

 

Shoebox, I couldn't agree more! There is little doubt that an engine will run if you just throw the correct set of springs in. But if you desire the Nth degree of high performance and durability at high RPMs, one must verify the correct installed spring height.

Not checking reminds me of that old saw..."Ignorance is bliss"

 

I have never done this and have only installed one set of springs and it was on a Gen 1 350. I am curious, what do you do if they are off? Also, are these locators something used speicifically on alum heads, or what exactly task do they perform. I havent ever had to mess with them.

Ben

 

Check this CompCam's tech site for info on setting up springs.spring install info

 

Well, I read through that. So what do you do if you have taller valves? I would assume that they make taller springs? Are the locators something that is required or just a good idea? What difference does that make compared to just letting the spring sit in the spring pocket assuming it is shimmed properly? Sorry, but I have not done much with this kind of stuff and hadnt really been inside a motor to much until about a year ago.

Ben

 

well I installed some springs on my big block without checking for the height, I had the toll to check it, but couldn't find it so I just took my chances, well It took one good run down the road winding it out to about 5600 rpm and bent about 8 pushrods, so to everyone that wants to take chances this can happen to you. But I did ask Cmotorsports about my cam and they said with most of their cam sales people usually don't check for height. My cam was pretty big it was something like 320/340 610/620 I don't remeber the exact numbers but I was really taking chances. Our pushrods are pretty cheap at 25 bucks, but it is kind of a pain to have to change them again. I suppose other worse damage could occur like bent valves or damaged pistons, so for the little extra work it should be done when doing the install, I guess with most guys here, you can get away with not checking, I still can't find my tool, so I might take chances again, unless I can rent one.

 

If your valve stems are long, you might need to add shims and/or go with a taller spring with a higher installed height.

Many believe that a good spring locator will keep the spring from walking around on the head at high RPMs.