I'm not sure about the 1/8 mile requirements but I did have to have the funny car cage added to get my old S/P Cuda cerrted to 8:5 ET., maybe it was to 7:50 ET  25.5 cage (halo) only req'd for quicker than 8.50 (25.5 will cert to 7.50). For the 1/8 I believe it's quicker than 5.49 et and more than 125mph that requires a 25.5 (or 25.4) chassis.
'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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