rklessdriver wrote:
Yes you should change the valve springs if you go to 1.6 rockers on an LT1. If not the factory LT1 springs are very close to coilbind and in some cases where factory tollerances stack up the wrong way, too close... not to mention depending on how many miles and how much hard use they have had, they could not have enough spring rate to control the valve train in all instances.

The factory LT4 springs actually set at a slightly higher seat height (1.780) via slightly different retainers and they are different wire dia.... thats how they get the extra lift out of them (up to .525) They are cheap, and solve all the potential problems of keeping the LT1 springs with 1.6 rockers.


$37.00 LT4 spring kit PN 12495494

$18.00 LT4 retainer kit PN 12495492

You need both.
Will