You have the strongest transmission available, the NV3550, from bellhousing back. If that's the case you need to use the thinner 4.0 flywheel with it. It's already thin, why would you want to thin a 258 flywheel? The only difference I see is that you would be able to use the original starter. The 4.0 starter is a much more reliable and longer lasting unit so that wouldn't make sense either.
My understanding of the flywheels was that there was a year in which the 258 thicker flywheel used the 4.0 starter gear location.
Is that correct?
I'm putting info together from different sources to come to that conclusion, so I could be wrong.
My @$$umption was that by taking the thicker 258 flywheel with the later starter gear mounting and machining it down, I'd have a lighter 4.0 flywheel. The two units are listed on Summit's website as starting at the same weight.
Did the starter ring gear change really happen at the same time as the change from 258 to 4.0?
I am having the front axle rebuilt so everything got removed including the axle. You absolutely must take your CV shafts off to get your wheel bearings and spindles off, so you're only saving five bolts that hold the axle on. I left the lower control arms on but I did grind off the rivets holding the ball joints while it was still in the car. You could leave the coil springs on, but realize that it's impossible to get your CV shafts off unless you push up against the coil spring with a jack. I held the entire car up by an engine hoist attached to a strap around the front bumper. I picked up the body off the engine as the drivetrain sat on rollers. You could feasibly leave the radiator but I removed it because it was being replaced and its in the way of removing the power steering pump conveniantly. I left the power steering pump tied to the fender wall and the steering box still inside the car. The pitman arm was popped off the power steering box. You must remove the power steering pump because the engine won't fit past the steering box on the way out the bottom of the car.
My intent is to get the powertrain out quickly.
I'm thinking that any bolts, such as the axle bolts, that can be left in place to remove the powertrain will be easier to access with powertrain out of the car and on the shop floor (or up on a sturdy work table).
Interesting that you popped the pitman arm off. I was thinking that I'd end up unbolting the gear and idler arm mount from the body. Having the gear off would be an interesting opportunity to reinforce the body.