im trying to figure out can you use a straight cut final gear in a regular tranny..and if you can whats the pros and cons about it

 

The aftermarket gear set options are designed to mostly be direct fitment into the OEM cases.

Straight cut is loud, so sometimes it can hamper diagnosis of other problems with trans or engine (if any). But, the gears are usually made from 9310, which will be stronger than the OEM gear provided it was designed and manufactured well.

 

Yes.

Pros: Slightly less friction so slightly less parasitic loss. You won't notice a difference though. Should be stronger than stock.

Cons: Loud. Countershaft and diff will want to push away from each other.

 

why would the countershaft and difff want to push away from each other

 

The ring gear and countershaft are straight cut. Straight cut gears push away from each other, helical gears push up/down on each other.

Unless you have big power you don't need to worry about that. Big power + straight cut FD = case needs to be braced (not talking about the clutch housing).