69 dz302 dual valve springs

[deadmetalprez1952]

Hey guys, can stock 186 castings accept dual valve springs? My heads were machined for dual valve springs in the early 70s. I have an opportunity to buy a freshly done set of 186 castings that are stock but my camera recommends a dual spring. Are there modern dual valve springs that fit into the 186 heads with no machine work? I can buy the heads for $400 which is probably cheaper than I can have my original heads rebuilt for...

[z28z11]

Depends on what your dual springs are - HiPo small block Z springs have the flat return inner spring. I replaced my originals with a single wound Erson tapered spring that ran very well, no problems.
I also used Perfect Circle seals that did not require machining the valve stems.

Regards,
Steve

[69Z28-RS]

I think the flat inner spring is properly called a 'damper spring', which basically helps prevent the spring system from resonating...

[x77-69z28]

What are the dates on your old heads? I need a set of April dated 186's.

[deadmetalprez1952]

x77 I sent you a message with date codes from my old heads, the new heads I bought are dated d228 and i218

[x77-69z28]

Deadmetalprez1952, make sure those 8's are 8's and not 9's. Very hard to tell on a casting number.
Buddy