[Cliff R]

Setting up the 200-4R for use behind a 455 is not "black magic". It started life as a tiny little transmission which was never intended to see that kind of power. It was a "stretch" to use them in the GN's, and every single one I ever knew who ran their GN's hard or started making engine upgrades smoked the 200-4R in short order. Back in those days, even well prepared units would typically last no more than one, and two at the very most, seasons of racing.

As with most anything else, the factory upgraded them several times, they started to get pretty decent hard parts and shift programs by 1986. Units made prior to 1986 will REQUIRE a hardened stator shaft, hardened pump rings, hardened sun shell, probably a direct drum, and a few other forged/billet parts if you want it to live at all behind anything making over 200HP!

As mentioned above, using a builder who knows them, doesn't matter what year you start with, they should be using the good stuff everyplace anyhow. If you are building your own unit, or using local assistance from a trans shop, starting with the later units may save a few dollars in hard parts, that's about it.

It's no secret I'm not overly fond of these units. There are parts out there for them that will survive 600 ft lb torque engines, but I still don't get a "warm and fuzzy" putting one behind a 455 that will see considerable strip action with good traction. It is THE transmission to use, if you have a relatively "mild" set-up, and only see the dragstrip once in a while with street tires or less than perfect traction. You just can't beat the small size, ease of installation, and the gear ratios those units provide.......Cliff