If I'm reading the OP's question, looks like the question is will a 46RE fit on a big block. The answer to that question is "Not right out of the box." All of the 46RE's bell housings utilize the small block pattern only. You will have to either get an adapter to fit your BB, plus there is always the hassle of the starter not being in the correct location -- I do not know from first hand knowledge, but I do believe you will be getting to know your grinder in a new way with the BB to get the starter to fit properly. Do some research on here to see what the deal is from someone who has used the BB to SB bell housing adapter and get the information from the horses mouth...........
The other solution involves cutting off a big block bell, cutting off the small block 46RE bell, and then carefully installing a big block bell on a 46RE by welding it on. Sounds like fun too -- but at least the starter will bolt right up with no issues if you're lucky enough to get the BB bell indexed correctly.......
Best of luck!!!!!!!
JW Ultrabell. You cut the bellhousing off the trans, then bolt the ultra bell on using the front pump bolts on the trans case. You don't have to worry about indexing. However if you use an adapter plate, you are correct, you need to grind off the lower driver side block mounting ear to put the starter in the SB location.
