[davepl]

I've never owned a 4x4 but I believe the motor is set back further, and of course is always a small block. I wouldn't assume that it'll work that way.

If it's a normal 2WD SWB I would highly recommend you get the factory mounts, both frame and engine. 1970s are very expensive so there might be a different year that's reproduced cheaply.

Furthermore, setting a bigblock back with 4x4 mounts, if it even worked, would likely not clear the firewall and the trans tunnel would be questionable too I think.