i plan on using my j heads on my 416 (340 stroker) and dont know what to use for springs... any ideas guys? also is there anything else i should do to the heads?

What CAM are you using ??? Get the springs the cam maker recommends ...

Agree: Contact the cam manufacturer. They will tell you exactly what you need.

comp 901-16 drop on a stock head with no machine work and use stock locks/retainer and valve seals

wish I had done more home work when I went roller cam,the lunati springs were double with a damper and need machine work and pc seal

I did the cam swap with out R&R the heads so I need a drop on spring

they were with in 10 plbs of the lunati spring rate...so lunati uses the same spring for all the sb cams,flat or roller

now I got 130$ double springs and damper for door stops

but yes need to match the spring rate to cam specs

seems the comp springs will handle all the cams I have looked at for the sb that are not to radical of a cam

need some doubls with a damper?

Comp 901s are similar to the Lunatis duals, but not strong enough for any profile larger than the XE268 they sell. They are a basic performance spring, nothing fancy or stiff.

On the J heads... You will need double springs for the cam that 416 should be getting (something larger than 245°@.050, which is very mild for a 4" arm). So have the spring seats cut and the guides reduced in size for them. Then get the springs the cam manufacturer says to.