I'm looking into putting together a 351 V8 with a 4 barrel carburetor for my 1996 F150. I'm also looking into seeing if I can get ahold of a T5 5-speed manual transmission rather than using the Mazda transmission that's in it right now.

 

OK.

A stock T5 is no stronger.

 

Do you know if Ford ever did a similar transmission compared to the Muncie Rock Crusher for GM?

 

The T5 transmission is barely strong enough for the 5.0 HO engine. It will not hold up behind even a non-souped up 351W.

The venerable Top Loader 4 speed is Ford's heavy duty transmission of the 60s through mid 70s; their version of the "Rock Crusher". It was used in trucks and high performance sports cars. But since it has a cast iron case, it is heavier than all the newer transmissions with aluminum cases, and it does not have overdrive.

 

The Toploader was never offered in trucks. There was an overdrive version based on the car transmission in the late 70's in both trucks and cars and later modified further in the early 80's in trucks with a top shifter. The SROD in the Mustang's was based on the old Toploader.

 

There are upgrade kits for the T5 apparently, I only know that because of a friend with a Mustang that has researched it quite extensively. Of course I bet you could buy a aftermarket trans for what some of the higher spec'd T5 kits go for so I'm not sure that would be terribly cost effective.

 

The T5Z is sold through Summit Racing, American Powertrain etc. It's the strongest Ford version of the T5. I understand the T5's used in the SN95 Mustang v6s are rated at the same torque rating as the T5Z when I emailed Tremec. I have one out of a 2000 Mustang 3.8 V6 that I'm going to put behind a fuel injected 331. It also has a different bellhousing, clutch diameter and electronic speedometer than the 89-93 5.0 Mustangs. Mine is a 78 shortbed that will be used as a daily driver and won't be pulling a trailer, speed shifted or raced so it should survive. If you're using your truck for any heavy duty truck use or don't want to run into any swap "issues" use I would stay with the Mazda trans and just throw a rebuild kit in it.