My "new" '74 Duster- or why I need a project like a hole in the head

goldduster318 said

25.6" tall tires so 2000 rpm at 75 mph, perfect for cruising at speed. With EFI I can run at 1400 rpm no problem so any speed over 50 you can run in 6th. This way if/when there is ever power tour or something it'll get good fuel economy and I won't go deaf lol

I'm at 9.59:1 in 1st with the 2.97 first and the 3.23 ring and you're at 11.438 with the 2.66 1st. I don't know about you, but I basically blow the tires off as it is. It might roll out a little better with a 3.55 but nothing to complain about.

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I think we've had this discussion before, but my 340 does not like to pull very hard below about 2,400. I've tuned it quite a bit and the AFR's look good with my 750 DP, but my vacuum at idle is like 11 with the cam I've got. That roller cam you have has a better bottom end than the hydraulic flat tappet I run. I was at 10.96 when I had the 833 with a 3.09 first and 3.55's, it works way better at 11.438 for 1st. That's actually where the 4.30's came from, took 1st gear in the right direction and still cruise at 70 at 2,350. It spins the 295's if I drive it like I stole it, but it can take off smooth without slipping the clutch, which was necessary with the 3.55's.