Being fooled in 2008 with a garage/shop...we found this today !!
You’re selling the 904 short, that’s why you can’t believe it.
While it would be better to have some of the internals upgraded beyond stock even just a basic shift kit improves the shifting enough for the stock stuff to last a lot longer. Same for the better converter.
And which shift kit is it? Makes a difference. The 904 with a few minor upgrades is more than capable of handling 410 hp, and you’ll have less power train losses than with a 727. Also depends on the use of the car, street use with street tires is totally different from drag racing with drag radials or slicks. For street use there’s no need for a 727 at all with that level of power
Plenty of guys run 904’s with a whole crap load more HP than 410.