Hi Guys any help would be appreciated.
After a dozen or so passes down the 1/4 mile track in the 3500 lb 63 Dodge the best et 9.92 best mph 135.34.
engine peak hp @ 6800 rpm shifting @ 6800 rpm crossing the finish line at 7350.
We are planning on running the car this weekend for a 2 day event. should I be to concerned with the RPM at the finish line? I don't want to hurt the engine! We are planning on changing the rear gears to 4.10's or 4.30's {what would you suggest}.
Could the gears be changed at the track if I went prepared? I have a mechanic who would help with the setting up of the gears but don't want to start something that we can't finish. The rear axle is a Dana 60.
I am also trying to tune a top end miss from the engine, once in hi gear the engine seems to struggle and doesn't gain rpm as fast as the 1 to 2 shift. fuel pressure @ 7.5 1150 jetted to 96 squared. timing @ 35.

thanks for any input.

should have included:
rear tire size 32 inch tall
torque flight transmission.

Changing gears in a Dana at the track is NOT for the weak of heart. The whole rear end must come out.

If there are no power valves in the carb, I would try jetting up two steps at a time see if the miss goes away and you pick up mph

yes no power valves.
will do!
I have a set of 98's I'm just amazed it needs so much fuel, those jets are huge.
the plugs by no means look to rich so this may be the answer.
thanks

572 at 3500 lbs with you in it? Of course it will turn less rpms with a 4.10 gear,but what are you 1/8 mile times and mph? How much conv slip? Have you tried less timming,shorter shift? What heads are on the car and headers what size?What brakes do you have? I would look at the 1/8 mile mph vs the 1/4 and see how much steam its making after the 1/8 before I chaged the gear.

yes 3500 lbs ready to race
Indy 440-1 reworked to flow 426
brakes Wilwood dual master cyl. 4 wheel disc.
1/8 108 mph 6.80's if I remember Dang left the time slips at the track with the car.
60 ft 1.45's and less only saw a couple in the 1.30's on a good air day.

launch the car @ 4200 shift will try and drop the shift RPM That may help thanks

Well there is the problem 6.80 @108 isnt fast enough. All the speed is comming from 3rd gear,so I would see what I could do about a better 60 foot and 1/8 mile time and MPH. again I would try less timming and a shorter shift to see what it does.

will do!
will be at the Fire and thunder race in woodburn this weekend.
the track and weather conditions were bad last weekend
hopefully for this big event the track will be prepped better.
Can't do much about the poor air
thanks

I would try more timing and 7200 shift points. You always shift past the peak to get the best overall HP.
What gear do you have now??
1.3 shorts and 9.92 you sure your 1/8 mile was not 6.3???

4.56 gear now
decided on 4.30's will have them changed next Monday.

Quote:

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1.3 shorts and 9.92 you sure your 1/8 mile was not 6.3???

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I agree, there's something wrong there if it is 6.80.

ok I screwed up the 1/8 mile are closer to 6.40's best 6.38
I'm horrible at remembering numbers