Ok. So I've been looking for a good set of valve springs to run with an xe268 cam for my magnum head swap.

I am aware that I can use the R/T springs with the 2.2l retainers and achieve my goal. But the price for new R/T springs is expensive.

I am also aware that If I'm running a .440 to .450 lift @ 1.5 cam (.470-.480 @ 1.6) with stock GM 3100 springs and retainers this would also be adequate.

Now I have done some measuring and such.

It seems that 981-16 (comp cams part #) for chevy v6 and small block applications could be a viable alternative to run the slightly higher spring rates for the xe268.

1.254 spring OD .880 ID

105lbs @ 1.65
294lbs @ 1.20

These pressures are comparable to the 901-16 springs for mopar.

The stock magnum springs measure
1.310 spring OD (bottom) 1.145 spring OD (top) .883 ID (top) .958 ID (bottom)

What do you guys think? Would the smaller diameter chevy spring be a good idea? They are fairly inexpensive, springs and retainers would run about $110.

The stock magnum springs will work for a .480 valve lift. We have been running them for years with .513 lift camshaft. Remember, you loose 5% lift at the retainer on a small block mopar. You should be ok. Just make sure the maggie beehives are not worn out.

If they fit the head seats and retainers and have the correct specs the spring don't know what motor it is on or care.