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402A2 Cam & Valve Spring Recommendation

2714 Views 4 Replies 2 Participants Last post by  Cable
Taken from another topic about the 402A2 BBC solid cam, didn't want to step all over the topic.

UDHarold said:
Lunati has a spring, part # 73124, that is about perfect---At 1.900", it is 129 lbs(set between 1.900 to 1.920), and at 1.350", on the exhaust valve, it has 320 lbs. Other cam companies have similar, or identical, valve springs.....

Harold, on Lunati's site they recommend the 73121 for the 402A2. Is the 73124 a better spring for the A2? Why?

Also, I wanted to ask about #99893 Crane springs (391 per inch). In the past I used a set with the A7 cam in a 496 years ago and everything was great. I removed the inter springs for break in though. I have access to another set (new), but don't want to use the wrong springs with the A2 either.

Thank you for any help in advance.
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I sold the 73121 for years at UltraDyne as the 920-921. Both springs are available from Pioneer, their manufacturer, who I bought directly from. I used the 73121 on the higher-lift UD BBC solid lifter cams. It had a little too much pressure for the lower-lift stuff, and requires the "Inner-Out" break-in method. I would not count on a clean break-in with inners installed on a 73121.
Lunati recommends the 73121 for all their BBC solids, I believe.
The 402A2 DOES NOT require the 73121s, and the 73124s are a better match.
Your Cranes work well, also. I'd ALWAYS remove the inner spring before break-in, on ANY solid or hydraulic cam, for safety's sake. Roller cams do not require break-in, so you can run full spring pressure from the git-go.

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