Good numbers  According to wallace our 580 (4.530 x 4.50) 12.5:1 makes 920hp (on a good day) it's very similar (even the headers) but with a T/R and 2 x 1150. We use an Indy cm 3 cam with 1.6 arms which works out at .768" gross lift. I'm considering switching to 1.7 arms (.816" lift) ..... so maybe a 25-30hp increase  Does anybody think it would be worth it ? Apologies for the hijack. Some car info below in sig. TIA.
'74 Challenger..9.46 @ 145.9 1/4, 6.001 @ 118 1/8 so far. 4023lb !!! # N/A, Marsh performance 655ci, Indy Maxx, T/R, Indy 600-13 X's, Street legal, pump gas, full interior, Cal-Tracs, mufflers, 3:73's and real 10.5 radials.
9.51 @ 142.4 1/4, 6.003 @ 114 1/8 with our old mule KB, 572-13, 580 wedge.
RHD '68 Barracuda Fastback 323ci street/strip. Best ET 13.88 @ 99.03
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