Author Topic: 69 dz302 dual valve springs  (Read 1082 times)

deadmetalprez1952

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69 dz302 dual valve springs
« on: December 27, 2016, 02:57:55 PM »
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

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Re: 69 dz302 dual valve springs
« Reply #1 on: December 31, 2016, 10:16:24 PM »
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



1968 Z28 M21/U17 BRG/W
1969 Z28 X77/M20/VE3 LeMans/W
1969 L78 X66/N66 Cortez/BVT
1969 Z11 L48/M35/C60/C06

69Z28-RS

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Re: 69 dz302 dual valve springs
« Reply #2 on: January 01, 2017, 02:45:42 AM »
I think the flat inner spring is properly called a 'damper spring', which basically helps prevent the spring system from resonating...
Gary W / 09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette convertible, silver/black 350 hp,
60 Corvette white/red, 72 Corvette coupe, '70 Mach I 
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x77-69z28

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Re: 69 dz302 dual valve springs
« Reply #3 on: January 01, 2017, 04:11:00 PM »
What are the dates on your old heads? I need a set of April dated 186's.
69 Z/28 X77 burnished brown, 711 int 05A bought in 78
70 Z28 forrest green, green int, M40, bk vinyl roof PROJECT
99 SS hugger orange 6spd NO TTOPS bought new 1 of 54
15 z/28 Arctic white, A/C 505 HP #251

deadmetalprez1952

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Re: 69 dz302 dual valve springs
« Reply #4 on: February 06, 2017, 06:54:17 PM »
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

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Re: 69 dz302 dual valve springs
« Reply #5 on: February 11, 2017, 09:24:34 PM »
Deadmetalprez1952, make sure those 8's are 8's and not 9's. Very hard to tell on a casting number.
Buddy
69 Z/28 X77 burnished brown, 711 int 05A bought in 78
70 Z28 forrest green, green int, M40, bk vinyl roof PROJECT
99 SS hugger orange 6spd NO TTOPS bought new 1 of 54
15 z/28 Arctic white, A/C 505 HP #251