stock springs .500 lift ?

[Busey]

I found this response from Crane on another forum, its a couple years old. I thought it was interesting that they recommend stock springs with that cam. Wouldnt you have bad valve float at higher RPMs?

Thanks for your interest in our products. Now there is one thing that you must keep in mind on this application. The factory changed in 1999 to a different front on the cams. So what you do is you run the earlier cams and you have to just make sure to get a 1998 or older timing chain and gear set. The second thing is on the 4.0 head, the stock springs will accomodate up to 500 lift with a slight modification. You need to mill the bosses on the valves down aprx.40-60 thou. to make sure the retainer doesn't crush the seal. Use our cam part# 753901 with lifter part# 99278-12. This works with the factory computer and EFI with no problems. Makes a great upgrade off idle to around 4800 rpms. Hope this helps and if you need any further assistance, please feel free to contact us.

[unlimitedrubicon]

That *may* work. You will certainly need to verify clearances that nothing will bind and that the seat / open pressures once the pad is modified are appropriate for the camshaft. Personally if I was going for .500 lift I would just go with the tried and true Mopar Performance setup. They drop in, you can find replacements easily if needed, and you can always go back if plans change since there is no machining needed.