The exhaust ports are higher and a different pattern than W2. You may be able to cut flanges and replace with W9. 1 7/8" is fine for 358.

If you are capable of doing the drysump,fine. If not it is possible to convert to internal pump. This depending on the rear cap you may have to swap and re line bore which is costly. Another option is a wet pan with a single stage external pump. With stock k member and steering box it will be very difficult to use the dry sump.