Heres some ideas to prevent this starting problem: Get a 1000 cranking amp battery, some bigger battery cables, a HI-Torque Starter,HD Solenoid and install a HD/heat soak spring in the solenoid(you can get from GM or places like Year One). Also check other items mentioned above in other posts.
I run a 70 455 with RA3 manifolds and have not had problem because I had heard of others having the problem and decided to do everything possible to prevent it .I hope this helps.
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