1.6 exhaust 383 valve question

[Gary Stavely]

Hi I am looking for some advice on valve springs and retainers for my 915 heads, I have upgraded my cam and will include specs. I was kinda under the impression the 440 heads were the same as the 383 but apparently not... The stem diameter, free length and closed pressures are different between the 383 1.6 exhaust valves on the left and the 440 1.75 on the right on the screen shot, I am thinking this is the difference between hp and non hp engines besides pistons of course? Maybe someone on here can point me in the right direction as I kinda want to keep the 1.6 valves and i like the cam but I am finding it hard to find the right springs and retainers, I ordered springs to match the cam but they are for the 1.75 valve heads.
Thx!

 

[PurpleBeeper]

I think you're just fine with the springs you bought to match your cam (someone please correct me if I'm wrong). I'm not sure if the valve keepers are the same though (angle & number of slots)

 

[Gary Stavely]

I think you're just fine with the springs you bought to match your cam (someone please correct me if I'm wrong). I'm not sure if the valve keepers are the same though (angle & number of slots)

I did buy all new valves as well that included the keepers, I am hoping the stem diameter is correct... those spring may require machining as they are wider.

 

[R413]

Stem diameter is the same, second line from the top .371-.372

I’ve bought 1.60 valves brand new before.

 

[Gary Stavely]

Stem diameter is the same, second line from the top .371-.372

I’ve bought 1.60 valves brand new before.

Thanks I do apologize i was looking at the lift at zero lash, my bad!

 

[Gary Stavely]

My understanding is they used the longer springs to accommodate for the closed seat pressure, there is a fairly big difference in the free length, closed pressures and width of the new springs, thats what makes me worry a bit.