Thanks in advance,Here we go.1970 f250 4000lbs 390,.030 over CJ heads, cast iron,milled .015, 11.5 compression,electric fan,alternator ford windage tray, high psi pump,Hooker s-comp exhaust open headders, C-6 with a 4000 stall conveter with trans cooler, cam lift 587, 248 duration,roller,F248,low riser intake with 8v 2-550s, original,fresh,with Hilborn type scoop,no hood,corectly ?? set up slapper bars with DANA60 3.54 gears POSI with 31x10 slicks. what would it be with a lower stall conveter?

It would cross the quarter mile mark in second gear. You either need a lot more gear (say 4.56's) or a much shorter tire (even 26's are too tall). Tires are easier and keeps the gearing OK for highway use. I'd think the ET gains would be worth changing for.

I also have a DANA 60 with 410s that i could swap into it. 456 seems alittle deep, what do you think guys??

then pick a MAX torque converter to be about 500 rpm less then that, assuming your not too far below torqe on your cam.



Now if its a drag truck then you 'might' be ok with the 4,11, but a 4.30 or a 4.56 would be quick!









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1967 FE 390GT engine: 416 CID 233/238* @ 0.050 Solid Lifter w/ 4 spd TL.

1968 GT/CS Mustang. 289/c4

1995 Mercedes e320 I6 DOHC, 216 HP wagon.

2003 Tundra SR5, 4.7 DOHC, 4x4.

Another Galaxie (one day.)



Oh and a Bicycle - daily driver to save gas for the 'F'un 'E'xcursions.

what is this??

m

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1967 FE 390GT engine: 416 CID 233/238* @ 0.050 Solid Lifter w/ 4 spd TL.
1968 GT/CS Mustang. 289/c4
1995 Mercedes e320 I6 DOHC, 216 HP wagon.
2003 Tundra SR5, 4.7 DOHC, 4x4.
Another Galaxie (one day.)

Oh and a Bicycle - daily driver to save gas for the 'F'un 'E'xcursions.

yes, i want max E.T.at dragstrip,so 456gearing is what you reccomend??

Howard,
The "G" says:
Torq 454 at 4200
Powr 444 at 5700

Sounds like a Lightweight F-250, our stocker longbed is about 800 lb heavier than that.
But assuming the weight is right and that it hooks with the slicks - and that they behave like I guessed (they wrinkle and then grow differently depending on a bunch of things I only guess at) the Gonk calculates:

3.54 gear
2.04
8.48 at 82.4
13.27 at 101.4

4.10 gear
1.90
8.25 at 84.2
13.04 at 100.1

4.56 gear
1.82
8.12 at 83.9
12.90 at 101.3

I'd go run it with the 3.54 and then the 4.10, if the change is as above then you can bet the 4.56 might help it as calculated above.

If you have it out can you confirm the weight but also check the rpm thru the traps (or known accurate speedo) under full throttle?

In either case the "G" agrees with what others have posted, 3.54 is ok but too tall for the strip.

THANKS!!