Last time I was using standard ram air manifolds with 2.5” headpipes and I think it lost about 15 hp over headers . I was really surprised this time it only lost 4hp with the better manifolds and 3” pipes over headers.. It made the same 570 trq as it did last time but got a decent bump in hp. Peak rpms is now 200 rpms higher with the new HR cam.
The closest track to me is new Oxford dragway,about 50 miles.
Looking at the 2019 dyno sheets it looks like it’s a little lower oil pressure this time. Maybe a 8 psi average lower now through out the pull. The mains are .0028 but the rod clearance is .0029,, last time it was like. .0023 rods. That might be causing the lower pressure. Idling today was around 19-20 psi at 800 rpm at temp.
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72 lemans,455 e-head, UD 255/263 solid flat,3.73 gears,,,10" 4400 converter,, 6.68 at 101.8 mph,,1.44 60 ft.2007
(cam 271/278 roller)9"CC.4.11gear 6.41 at 106.32 mph 1.42 60 ft.(2009) SOLD,SOLD
1970 GTO 455 4 speed #matching,, 3.31 posi.Stock manifolds. # 64 heads.A factory mint tuquoise ,69' judge stripe car. 8.45 @ 88.1 mph on slippery street tires.Bad 2.19 60ft.Owned since 86'
Last edited by scott70; 05-19-2026 at 04:11 PM.
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