20+ years of "Building 904/727 for drag racing use"

Duster346 said
Same thing applies for the 904 OEM Input... I've seen them break in 11 second cars but not break in 10 second cars. You can be on the fence real easy with a 904. Going from a 500hp 904 to an 800/1000hp 904 is a huge jump in price when adding 300m shafts, billet drums and rollerized geartrain.

The thing with the 904 is, you cannot just add a billet fwd clutch drum and 300m input shaft as it has a bearing that has to ride in the pilot of the 300m output shaft. So the input and output shafts for the 904 must be purchased together

Building a 904 now for 800+hp, even though he won't make that much power yet.. but he has room to grow.

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I’ve made a pin out of Thompson shafting to use a billet 300m input shaft with a stock output shaft. The factory pin is just pressed into the output shaft. I simply pull that out, press in a piece of Thompson that had a hole drilled through for oil, and buy the selective
Thrust bearing assembly. FYI
Off course a 300m output shaft would be much stronger, but it is doable with just the billet input.