How much HP can a SOHC hold

[maldo]

The bellhousing attaches to the middle of the transmission. It is not like the rwd or old big block transmissions where you could simply unbolt the housing without cracking open the case. If you want to remove the bellhousing you need to remove 5th gear and reverse then slide the transfer case off. Yes the guts are quite similar but without sitting the two transmission side by side, opening them up and comparing the bolt patterns of the case you won't get very far. There is most likely a reason why Mazda didn't use the F or G series interchangeably between the K and B series engines, a good physical guess is that exterior designs were differrent. I am sure that there are better options out there than swapping a housing. If you feel inclined to go for it then do it.

[curtklze]

It was my understanding that the 1.8 BP and BPT came with G25M-R and the K series V6 also came with a G25M-R but the bell housings were different, due to the fact that one is for a 4 and one is for a 6.