That is what I"d drop in. That should bolt together and drop in using existing driveshaft, motor mounts and exhaust. You need to also get a radiator with the lower on the other side. Try a 70 340 Duster. I'd replace freeze plugs, seals, gaskets and a double roller timing chain as you can afford before you put it back together and in. I'd adjust the bands in the trans, drain all the fluid out of the torque converter and trans and replace filter, pan gasket, front and rear seal. I like the intake and carb off the 273 better also. Thats it for starters.