Do you need all the bolts to safely secure the transmission to the engine?
 

So I find myself taking down my transmission more often than I'd like for various different reasons. There are 2 bolts at the top of the transmission bellhousing that are very hard to get to for me on my RX8. It also makes taking down transmission very difficult necessitating a large pry bar to flex the firewall so I can muscle the transmission out . The question is do you think I can grind off the 2 bolt holes at the top of the bellhousing so I can take down the transmission out easier? Would that be safe? Thanks in advance.

It isn't advised, there are other options to make your life a little easier, one would to look into putting studs in the top two holes. another would be to look at machining down the bell housing where those two bolts go through and then machine down the head of the bolt to give you a bit more clearance.

I only use four of the bolt locations plus the starter. The way my header is arranged, it's too difficult to get to one of them with an extension.

I have heard that some people reduce/eliminate the tendency for pre-FD engines to break dowel bosses by leaving the bellhousing bolt out in that area. Allows the metal to flex a little more, less constrained.

The Audi rally cars that used production transmissions had the top of the bellhousing machined completely out so you could remove the transmission without removing the steering linkage, which eliminates two of the five mounting points to the block. And this is with a longitudinal transaxle setup so the bellhousing face is loaded in bending and not just rotation.

http://www.mat.fi/images/gallery/65/1350a.jpg

Thank you. Machining to bellhousing with stud is an excellent idea. I will try that, and if that does not work, I guess I will leave those two out and see what happens. Thanks again.