valve springs

[Big Block Ram]

I have a mild 383 with a .494 lift cam. I have stock springs and the valves float at 5500 RPM's. Which springs do you guys recommend?

[Fast One]

Mopar recommends P5249848 for a lift range between .480-.540

[cuda66273]

Whose cam is it?

What do they reccommend?

The biggest problem with Mopar heads is the size and weight of the valve, some of these Chevy base circle cams create huge harmonic problems with the heavy valves and can float them at relatively low RPM....4-4500....

To much spring will hammer the cam out of it, too little spring will bounce the valves off the seat, wrong base circle can create low RPM harmonics.

Have a look at the valve tips....do you see a star pattern on them? If so you definitly have a float problem, but what is the source?

Sometimes throwing a set of unmatched springs at a cam causes even more problems. Find the source first then consult with Jim Doyle at Racer Brown, he'll tell you what you need.

Racer Browm 410-866-7660

Be sure and tell him Don and Allen from Oregon sent you or you may get shuffled off to the tech dept., you want to talk directly to the Man!