Hello everyone, I am dropping a 375hp 4.3 "long rod" v6 in my 2006 f150. Is there any kit to rebuild the m5odr2 to make it stronger or should I just grab a t5?

 

No rebuild kit will strengthen that trans.

What kind of use are you talking?

A T5 might be rated for up to 300 HP in a Mustang, but you are going to be 1000 lbs heavier, so hard use is going to be an issue with a T5.

T56 will solve your problem:

Modern Driveline T5 transmission parts & conversion packages

 

It's going to be my daily driver but will also be driven hard. If I run a T56, what gear ratio should I run being it's a six speed? And thank you for the advice in advance!

 

Gear ratio will depend on where this engine makes power and your tire size, amongst other items.

 

Well, if you come across a T56 at a good price, let me know!

 

So the M5ODR2 is the Mazda 5-speed, overdrive high-gear transmission in the V6 manual trucks? I doubt you will need a 'stronger' box. What is the new engine out of, or is it a crate engine? I'd guess I would go with the 3.55 rear or even lower. Your truck probably has the 3.31 which is pretty high.

 

It's a crate engine. I just worry that transmission won't hold up with a more aggressive clutch than the stock one.

 

It will hold up to a stronger clutch. It may not hold up to your left foot. If you are going to run this thing fairly conservatively, it will be fine. Racing or otherwise beating on it, you will be transmission shopping, plus other drive line items.