Does your 248 have a 4 bolt crank or a 6 bolt crank? That would be a place to start. If you are just going to drive around town, a 250 Chevy would do the job, slip-it in there and go. If you find a 292 someday, easy replace with new right front engine mount, 3 bolt exhaust flange.

Ed

'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires.
'47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle.
'54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed.
'55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.