I'm building a FI 408 shortblock for my truck and need advice on the viability of my valvetrain selection.The shortblock has 8.7:1 compression JE reversed dished pistons,TEA stage 1.5 6.0 heads with Comp 978 sprngs and the cam is a Comp 228/234 .588/.598 114+4 with Comp R lifters.I had originally planned to use Yella Terra rockers but after reading numerous posts about the need for adjustable rockers with R lifters,I've decided to go with Pro Magnum 1.75 rockers.When I did the lift calculations with the 1.75 rockers I come up with lift of .605/.616.Is that much lift going to be a problem,that's more lift than I've even considered running before.Thanks in advance for any advice you guys may give.

 

With the dished pistons and I'm guessing the heads haven't been milled much, I doubt that you'll have any piston to valve issues. The valve spring would need to be able to handle the XER lobe with a 1.75 ratio rocker. Run this same question by the guys at TEA and verify the springs you have on those heads are up to the task.

 

that's probably gonna be pushing it. those springs, if installed at the recomended height of 1.850", are only rated to .600" lift.

you should call TEA and talk to them about it. find out what height your springs are setup at. that will be a big determining factor.