If you want to stay "period-correct" a 283 would be a drop-in swap, assuming you can find one in good running shape or are willing to build one up from scratch. A 30 year newer option would be a 305- - - -which is basically a 265 with a 350 crankshaft. Lots of torque and relatively better gas mileage than a 327, and parts such as blocks and cylinder heads are much more available since that engine was used through the late 1980's at least. A 3rd. generation inline six such as a 230, 250, or 292 will bolt up to your transmission since they all have the V8 bellhousing bolt pattern, as well as a bunch of V6 engines. S-10 trucks tan a V6 with a 700R4, and if you don't want to go with the throttle body fuel injection, there are lots of intake manifold and carburetor options possible. You've got a big variety of options- - - -"Ya pays yer money and ya takes yer choice!"
Jerry
