I had my `70 Chevelle Dyno tested, with a fresh rotor, cap, and plugs. It is the zz502, with a Richmond 6 speed and a 308 Moser 12 bolt. They did 7 pulls. Changing the timing to 36 didnt increase any power, so back to 32 total, I have always heard that more gas makes more power, but by jetting down the secondaries two different times, the car made more power. The second pull it made 403.2 horsepower and 460.9 torque. After the jetting the last pull made 412.3 horsepower and 484.6 torque. The guy doing the test was trying to get the air fule ratio up to 12 to 1, it started out at barley over 10 to 1. Also, dyno tests, I have read, should always be run in a 1 to 1 gear ratio, and mine were, but what if my car had, say a 373 rear gear, instead of the 308? would that change the numbers? I realize that crankshaft power can only be estimated by these results, and I am happy with the results, the car pulls really hard in all gears, I know I cant shift it like I could when i was 20, but what do you guys think about a 1/4 mile time with these numbers? and my lingering question about the fuel? according to this test more is not always better. By the way it has an eaton posi, southside machine lift bars, lowering springs and adjustable uppers. Thanks for any insight...

For the part about if the gear ratios would change the numbers, I was told by a guy at a local chassis dyno that it only really affects when what power displays where in the power band, but not actual HP/TQ numbers.

My 3250# Vette with a Richmond 6 spd went 11.87 123.6 mph in total street trim, exhaust etc. My car made 491 rwhp and 460 rwt. Solid roller 454, ported heads, 1000 cfm Holley etc.

The dyno #'s can be effected by the rear end ratio, slightly. The deeper gears eat up a little more power, there-for less will reach the tires.

The stock ZZ-502 in my 72 Chevelle went 12.5 @ 108 mph, when my brother owned the car.

With 3.55 rear gears and a 400 turbohydra, through the mufflers on street radials.

I'd imagine you will be close to that if you can get the car off the line.
Scott's first pass was 15.8 @ 105 or something like that.
Really hard to get off the line without spinning the tires.

More fuel won't make more power. The correct air/fuel ratio makes best power at each specific RPM for the atomospheric conditions at that time.

From the many dyno pulls I've made, the high the trans gear you run in, the more power it will show on an inertia type dyno, ie 1:1 trans gear will show more power than 1st or second gear. I always try to test in the 1:1 trans gear. The rear gear will have little if any affect as the software takes that into account although I haven't backed to back a car with say 2.73's and 5:13's.