Austin@HPE

Im looking for valve springs that will support .670 lift also what are the best lifters to use for this lift also. I found comp has part number 26926 but they are not released yet any others?

1.8t

I think the PAC 1521's will handle that. They are supposedly the latest and greatest in the realm of high lift/quality duals.

405HP_Z06

iTrader: (11)

Here are the one's I know of that will handle that, assuming installed height is 1.800". In no particular order:

• PSI - LS1512ML
• Comp Cams - 26921
• Lunati - 74721LUN
• PAC - 1221
• PAC - 1521 (Barely, leaves .050 to CB @ .670 lift)
• Ferrea - S99100

Austin@HPE

only the ferrea says it supports over .660 lift

WKMCD

iTrader: (2)

I run PAC 1521's. They are good for .700 lift when setup properly.

405HP_Z06

iTrader: (11)

Take a look at the chart below, all data is based on manufacturer specifications. The valve springs that support .670 lift based on spring coil bind specification and calculation with .060 safety margin are circled. Sorry for the size, it's a lot of data. I included the PAC-1521 because it's within .010" of the others and could be used.

Assumptions: 1.800" installed height, .060" clearance before coil bind, load to support an aggressive lobe.

kelp

You'll wear out your valve seats with a public grind from most cam guys, especially at that lift. Maybe reduce your left a bit and have your heads last longer. Better get upgraded pushrods too, cheap insurance.

405HP_Z06 thanks for great data!

405HP_Z06

iTrader: (11)