Im getting a 1961 283 pretty cheap they have a 3bolt starter. i dont want to use the three bolt starter . So i guess a 2 bolt can be drilled and tapped. what flywheel do i use?
D&T the block for a later starter is going to really be a machine shop job to ensure the holes are located perfectly to keep the starter aligned correctly. Might be a real headache. I have D&T blocks that were setup for parallel holes to angled pattern and that's an easy task since I can install the starter with one bolt and check alignment and engagement before marking and drilling the 2nd hole. But never even considered doing both holes as I have no way to align the two holes.
Turn the engine upside down with the flywheel in place and make something you can support the starter with.....then just sit it in place and use the correct size transfer punch to mark the hole locations. Might want some type of strap to support the opposite end of the starter.
The starter you use, depends on the transmission you use. You didn't tell us...but should we assume it's a more modern aluminum case automatic? If so, look at the block, see if it has two holes for the starter to bolt to the block. If so, get a 168 tooth (14") diameter flex plate, and the starter and bolts for a 1970s truck 350 engine/350 transmission, and it should all work fine. I'd check the starter shaft to flexplate tooth distance, to make sure it's 1/8", before trying to start it, though, and shim if needed.