I just installed my 4gsk and i got the springs to go with but the diesel mechanic i know said you dont need these springs unless you are makin 70 or up lbs of boost. Do the springs make any extra power. do i really need these im not pulling with it.

 

The reason you need them is because the valves will not close fast enough with the stock springs above ~3200 rpm and you might hit a valve on the piston.
Some people don't do them and just keep a close eye on the tach, but i'd do them IMO. You really should to both intake and exhaust too.

 

yes if you plan on spinnin that motor over 3200 rpms anything over that you run the risk of floating a valve

 

I would def. do both intake and exhaust. Normally, the reason people only do the exhaust isn't for the 4k gsk, but because they are req'd for exhaust brakes.

 

I vote put them in good insurence and you already have them

 

does anyone make anything heavier then a 60lb spring?

 

Hamilton i think makes some heavy ones. they are $$$ though.

 

They do make some great springs and retainers for these 12v's. compare them to a set of 60lbs springs with titamium retainers and keeps and the price is very close.

 

With valve springs, there is a trade-off in pounds of seat pressure versus cam wear. Run the lightest springs that will get the job done. Running heavier wears the cam faster and sucks up more hp.

About the only reason I can think of to run heavier than 60# springs (which are mainly taller factory offerings that have more closed seat pressure) is to really turn up the RPM, but doing so will also mean that you need a lot of other high $$$ mods, starting with a crank dampener and moving up from there, as about 4000 RPM is the limit on the stock lower end before it starts making all sorts of weird harmonics.

 

i asked because i will be running 4k, for now...till i get my pump redone, within the next month my bottom end will be studded and girdled. a fluid damper is on it's way. i work t an industrial diesel machine shop, so i have the benefit of not having to pay for machine work, or having the rotating assy. balanced. i was just wondering if it would be good to go for a heavier valve spring straight off rather then spend the money on the 60lb and then upgrade to a heavier spring