help getting ready to order new gears

68 roadrunner. weighs about 3000lb. 500ci stroker.32 inch tall tires.trans brake.will run mostly 1/4 mile but may run some 1/8 what gear would you guys run.i was thinking 4.56 or 4.30 or ?

thanks fred. any one else have an opion

Just like Fred said... you base the gear to the RPM
at the finish line... you would like 10% over peak HP

that does help fred. and thank you agian.and maybe next time i will spell opinion right.

When plugging in your numbers in the Moroso Power-Speed Calculator or other calculators do you use the HP rating of the engine at the flywheel or the HP rating at the rear wheels after subtracting the estimated drivetrain losses. Thanks!

I ran a Road Runner that weighed 3,650 with driver per class rules. I was running Mickey Thompson Drag Radial P295/65R15 30 X 12.50R15 and was going through the traps at 7,200-7,400 rpm. The gears were 4.56. If you are running a 32 tall tire you may consider a 4.88 gear especially if you will be running some 1/8 mile tracks.

only problem that formula doesnt understand is
mmmmm TIRE GROWTH it measure it only at that tire size,
that 33 tal tire doesnt measure 33,
bet more like 31
havent seen a true 33 yet
as well as any others

i own three set 1 mt
1 goodyear,
1 hooser,
and have measured several others
at set air on tire they do not even get close
best i have is 32.3 thats the best
it s a hooser,!
mt is a 31.6
maybe i can buy tires from you
so i can get a true size??
never go off what that tire manufacture says
or puts on that tire!! except the date code

wounder if i'm the only one who has this problem???

Try buying your tires from Harlow Tires... they match
them up before sending them out.... for me I just go
drop my rims off tham pick them up mounted and balanced

That's where mine are coming from! Hope they match them up for me!

mr p
these came from mcormic (off spelled) racing
but we all have measured tire over the past years none of us see correct measurements
i dont understand this but its true
i dont just make it up on a whim
i can go measure 4 race cars in our bunch
none will measure up
we use old cloth measure go around the center
with tire at race air 10-12#
of course maybe this doesnt make a diffrence
1" tire

Tell us a little more info on the motor, which heads, what intake port size, camshaft type, lift and duration and carb and converter size

Quote:

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mr p
these came from mcormic (off spelled) racing
but we all have measured tire over the past years none of us see correct measurements
i dont understand this but its true
i dont just make it up on a whim
i can go measure 4 race cars in our bunch
none will measure up
we use old cloth measure go around the center
with tire at race air 10-12#
of course maybe this doesnt make a diffrence
1" tire

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Dont you ever stretch your short tire?