The Stovebolt Site Forums The Parking Lot Tons 'o Fun 4BT swap

The mounting pads are the same from '54 through at least '72. After that I'm not sure.

The clutch linkage varies and some of the bellhousings in the 60s are designed to use an hydraulic clutch. You probably don't want one of those. On the other hand a hydraulic throwout bearing can solve most clutch linkage problems and might be your solution. I'd just convert to an automatic if it were me.

After '67 the center hole on the transmission side is larger for the the SM465 and the SM420 would need an adapter ring of some sort (see Grigg's post above).

I'd look for a '55 to '59 bellhousing if I were making this swap. Others probably have more experience and might have other ideas.

Head clearance isn't as big a concern as distributor. The big cap HEI might hit the firewall. Of course a 283 did not come with one of those so that may not be a concern.

And you will still have steering box issues to deal with. I like the power steering conversion that puts the box ahead of the axle, but those kits are designed for 1/2-ton trucks and I've concluded would require some modification to work on a 1-ton.

Going back to your original question, that 4BT swap could be easier than the V-8 swap expect you can buy engine mounts for the V-8 and may have to fab your own for the Cummins.

My sense is you are looking for a swap that requires very little fabrication or re-engineering. You might be better off looking for a Chevy 261 which is a near bolt-in swap or perhaps a GMC 270 or 302, which is not quite as simple as the 261 but requires a lot less modification than a V-8 swap or the 4BT or a later six like the 250/292 motors.