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Apr 18, 2017 | 11:07 AM

red chandler

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big tires

i want to take about a 1990 f350 and swap in a 6.9 and e4od the reason im going with the mechanical engine is special but i want a 3 in body lift and a 6 in susp lift with 41.5 pitbull rocker radials would a 4.10 work

Apr 18, 2017 | 11:23 AM

pwjackson42

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Google engine rpm and speed calculater. With 4.10s and the overdrive of the E4OD you will be less than 1,300 rpm at 55 mph with 41.5" tires. I think with a 6.9 you will want to be closer to 1,600 to 1,800 at that speed. Looks like you will need something more like 5.13 or 5.38 gears.

Apr 18, 2017 | 03:43 PM

tjc transport

i ain't rite

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From: Marlboro Mental Hospital.

welcome to FTE
poor combination. it will have no power, and be slow as all get out.
plus the lift will make it very unstable.
i would go with a 7.3 with aftemarket turbo, 4 inch suspension lift with trimmed front bumper, 37 inch military takeoff tires, and 410 gears. this will give you good power, and still get decent fuel mileage.
plus it will be a very stable on road and off road platform .

Apr 18, 2017 | 04:49 PM

cadunkle

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From: NJ

Quote:

Originally Posted by red chandler

Why 3" body lift? Either do a proper suspension lift or don't do it at all. 41.5" will likely fit with 6". 4.10:1 gears will likely be fine if you have a turbo and get a higher output pump and good injectors. It'll be slow no matter what, even stock height, unless you do a performance or custom turbo setup. With any of the big 3 stock systems it'll probably be adequate though.

Apr 19, 2017 | 06:00 AM

hturner12

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From: Thomaston

The 90 had 7.3

Apr 19, 2017 | 06:03 AM

hturner12

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From: Thomaston

Sounds l8ke a call to Justin and have him build you a motor

Apr 20, 2017 | 12:58 PM

A48WillyzGuy

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My truck (in my sig) is probably pretty close to the final ratio of what you're talking about building; I may be just a little better off than you. The lower ratio of my 460 trans definitely helps on takeoff, and I get a significant amount of wheel hop when I am hard on the throttle. The truck isn't a slouch, but it's got a heck of a load on the engine at all times. I'm strongly considering 4.10's.
I'd look into 4.88's or 5.13's for your setup.

Also, generally there's no real issue with a body lift up to 3". More than that and you're asking for trouble though. I'm running my 37's with no lift fwiw.