Dale,

The tranny can be made to work. It isn't a direct fit. You will have to alter the floor (several options), you will need to find or have drivelines made. The general consensus seems to be to find the latest model of m41 you can. Better OD and better parts availability. As for the seat belts, they weren't retractible. You will have to find something that fits. The "hook" side was a loop mounted on the tunnel between the seats on my older car. I haven't found a later model that had original seat belts, can't speak for them. I do know they had a lap belt and a shoulder belt and weren't always attached to each other. As far as the bolts themselves, a grade 5 will hold anything you can do to it, but grade 8 is only pennies more and even more secure. You want to mount to a solid part of the car, not a rusted out part of the floor. On the bottom side, use the largest diameter washer you can find. This will spread the pull to a larger area.

If you would like more details on putting in the OD, I'd be glad to tell you how I did mine.

Leonard