Hey, I am looking at getting a new cam, most likely the LT4 Hotcam, but the kit is kinda pricey. The heads I have right now have been rebuilt ( 0 k's) and have 1.5 Roller Rockers and Z28 Heavy Duty Valve Springs. Now, with the 1.5 Rockers my lift will be reduced somewhat, I saw in a post somewhere by .030. I went and found the specs on the Z28 springs and it said that they were good for .550 lift. The LT4 springs are good for .525. So I should be okay to use the cam with my current parts?

Dustin

 

Z28 springs are only good up to .480 I think or .510 max..AFAIK

Daz

 

If you're gonna go to the effort on putting in a new cam, the price of new springs is cheap insurance that you're not gonna bend a valve. If you're getting the LT4 HOT cam, then the LT4 springs should be fine. But I would not use old springs.

 

I think daz is correct with the .480 lift numbers....but like Irocker said.....change those springs when when you change the cam, is good insurance.

 

.480 is the max for stock springs.

you could always pic up a good used hot cam for alot less. but no mater what replace your spring. its most likly they are worn out anyways

 

BTW....since we are on the topic of springs etc, what will "worn out" or "tired" springs result in...I am not talking broken ones, but ones which maybe should probably be changed??

 

valve float is the big one. the valve not closing fast enough because there is not enough presure.

 

Often the valve will bounce off of the seat because of weak springs.

Ramping (or not closing fast enough) isn't quite as common as people think it is.

Jon