I put my numbers engine in my '70 GS455 about a month ago and I finally got around to freshening up the old engine. It ran a best (for me) of 12.59. That's me turning it to no higher than 4800ish. I know too low. Here is what I found: 1. Standard bore block (71) with cast pistons. 2. TA 413 cam 3. The 430 (big port) heads with standard valves and 430 rockers 4. Standard timing chain 5. All GM fasteners on heads, rods and mains It is in good shape so I am changing the rear main seal (leaking), putting a plug in the left deck oil whole (leaking) and putting it back together maybe sell to someone local who needs a good running engine. I can't believe that it ran so hard with stock 3:42 rear and a 2800 stall converter.
