727 safer than a 904... never seen a 904 explode behind a street engine. 727 and that front drum can be fun.

A decent 904 build will handle a street 340 fine. Plenty of 904's running around on the street behind 400+ inch SB's. Probably use the same driveshaft as the 4sdpeed to boot.

It's not 1970 anymore and the huge dollars to build a 904 to live is simply not the case. Decent clutches/band and a tf2... I'd love to see a list of all these expensive parts required to make a 904 live. Put an extra clutch in the drum running the thin variants, man that's expensive. LOL Doesn't need an expensive drum to make it safe either... Wanna make a 727 so it's safe, front drum instant $500 bill to the build, you can build a strong 904 for that number alone. BTDT on building 904's

Of course a 727 is a tougher trans to hurt, it's also got bigger parts/clutches in it. Also has other drawbacks as well.

Pick you parts, pay your money.