Ford ZF5 Transmission

[pb4ugo]

@Hilndr1701 what's your intended use of your 40? 1st I'd pull the rear diff cover and absolutely confirm its ratio. Do you really want or need the 5.29's? If not I would be installing a more desirable ratio, b4 installing a trans with an overdrive. 4.11 3rds are cheap and plug and play. The replacement trans 1st gear is going to effect your your crawl ratio too.

It seems most folks recommending the h55 and mentioning shift tower placement aren't taking into account that the op is running an sbc which places the stk h42 tower 3 or 4" forward. An FJ60's trans top cover tower is further back and would be helpful. Imo, the h55s' 5th gear(.80) doesn't have enuff gear reduction in 5th gear for an sbc. The engine can handle a deeper overdrive like whats in the nv4500(.73) and offers a lower 1st gear. The nv4500/sbc conversion places the the shift tower very close to the 4 speed tranny humps stk location. In my case with a sbc/nv4500 I tried 3.70 3rds with 33" tires for a bit and decided to put the 4.11 3rds back in, to slightly raise my rpms at highway speeds and eliminate some down shifting on bigger hills. Another consideration was I'll likely be going to 35" tires in the near future.

 

[Hilndr1701]

@Hilndr1701 what's your intended use of your 40? 1st I'd pull the rear diff cover and absolutely confirm its ratio. Do you really want or need the 5.29's? If not I would be installing a more desirable ratio, b4 installing a trans with an overdrive. 4.11 3rds are cheap and plug and play. The replacement trans 1st gear is going to effect your your crawl ratio too.

It seems most folks recommending the h55 and mentioning shift tower placement aren't taking into account that the op is running an sbc which places the stk h42 tower 3 or 4" forward. An FJ60's trans top cover tower is further back and would be helpful. Imo, the h55s' 5th gear(.80) doesn't have enuff gear reduction in 5th gear for an sbc. The engine can handle a deeper overdrive like whats in the nv4500(.73) and offers a lower 1st gear. The nv4500/sbc conversion places the the shift tower very close to the 4 speed tranny humps stk location. In my case with a sbc/nv4500 I tried 3.70 3rds with 33" tires for a bit and decided to put the 4.11 3rds back in, to slightly raise my rpms at highway speeds and eliminate some down shifting on bigger hills. Another consideration was I'll likely be going to 35" tires in the near future.

Yes, this.