I just put 4.56 gears in my 99 4.6L and now I want a six speed manual to reduce highway RPMs. What is available to fit my truck?

 

huh????


I'm not aware of any double over drive 6 speed manual transmisions that will do what you want

 

The 6 speed ZF out of the Super Duty (which is a difficult conversion) doesn't even have a double overdrive - 1st gear is a granny and the rest of it is just like your 5 speed. Your only solution is quite expensive - a Gear Vendors overdrive.

 

Haha and it is!! I am in the middle of it and keep running into problems. Should be able to really put some time into working on the truck after this deployment though. Once I start again I will be updating the thread I started.

 

If you want to reduce highway RPM, why not gear it to something more reasonable? If 4.56 yields excessive RPM, obviously it wasn't the right choice.

 

T56 is a commonish swap

 

That's what I was going to suggest, 0.5:1 sixth gear ratio. I have one in my Camaro, great trans but IDK how hard it'd be to swap.