I just don't see why you would need a spring that can handle .600 lift and 7500 rpms on a .53x lift cam that will probrobally never see 6500 rpm. But as I said, I'm really not that educated as I would like to be in this department.

 

My research told me (and anyone who knows me knows that not many people do more research than I do prior to a purchase) that the 918 is one of the best all-around springs on the market for aftermarket cam swaps. What I was told directly was that unless you go higher than the rated lift on them, they are okay....that using 918's for a smaller-lift cam is just fine. And I was also told by my source at Comp to NOT use the 915's in anything - that any application calling for the 915's should get the 918's instead.

Oh, BTW, I have absolutely no valvetrain noise with my 918's, as some others have reported here and in the F-body section.

 

I guarantee that I do.....I've been looking for over two years at different cams, I can probably tell you more about different cam lobes than you would EVER want to know.....I just don't know **** about the springs for them apparantly

 

springs- they are usually made out of steal, although more exotic metals can be used, they are wound in a coil to provide a specified amount of resistance, they come in sets of 16 or can be purchased individually, they are sometimes marked with colored stripes for reference, and lastly, they are a required component in your engines valvetrain

any other questions Yelo?

 

Did you have the heads milled too? On stock LQ4 dished pistons with 67cc LS1 chambers (not including any cc removed from polishing) you'd be looking at barely 10:1 on stock MLS gaskets. If you choose to run a thinner head gasket like the felpro 1041 (which I would), youd end up with almost 10.2:1 and have a better quench area.

Otherwise, I think its a good combo. Even better since they aren't iron heads going back on.

 

BigTex: What is the bore size of the stock gasket ??, and the thickness ??....everytime I calculate it I come up with 10.41:1. I calculated it as a 4.100 bore gasket that is .065 thick, and AFAIK the piston comes out of the hole around ~.007.......all that together adds up to 10.4:1

Oh, and BTW....the stock LS1 chamber is 66.67cc

And NO wisecracks about the iron heads there buddy

 

and moregrip.........ah, nevermind.....I like you too much to say it

 

Stock multilayer steel gaskets are 4.040 bore and .054 thick. I used a -7cc dish on the pistons , and -.008 out of the hole.

I built a little spreadsheet a while back so I could just plug in several variables and get the correct CR. It accounts for bore, stroke, dish, piston deck height, chamber, gasket bore, gasket thickness.

This is a simple comparison:
You are at 9.4:1 with a 71.33 chamber now. By dropping 4-5 ccs in the chamber, you won't gain a full point. For instance, the LQ4 @ 9.4:1 has a 7cc dish. The LQ9 @ 10.x:1 has flat tops. That 7cc only accounts for roughly .6 to .7 of a compression point.

 

I was only kidding

If you need help, let me know, that's alot of work to do by yourself.

On a serious note, I would consider studs for your heads, as Flyer said. On my 67 Impala SS I had studs for everything including the thermostat housing, needless to say, I prefer studs to bolts when applicable. Besides, when you get the twins fired up, you might need them, or want them

 

Another reason for the studs is that you thread 'em in and then - voila - more wear and tear on the threads in the block from torqueing and loosening of the head bolts.

But they are more expensive and cheap is cool.