The 348 was a panic attempt by Chevy in 1958 to stop the bleeding in the sales department caused by the 57's getting waxed on the drag strip by the supercharged Ford 312's. The 348 engine was intended to be a high-torque medium truck engine, and was never intended for passenger car use. It had a really nasty habit of swallowing valves at high RPM, and putting a 3-2 barrel intake on the 58 Impala hotrods didn't help much in that department. Chevy racers were accustomed to the tight-winding 265's and 283's, and an engine that started floating valves at 5500 RPM just didn't cut it. Upping the displacement to 409, and then 427 to comply with the FIA 7-liter displacement limit in the early 60's didn't help much, so Chevy btrought out the straight valve cover 427 in 63, for the Daytona Firecracker 400, and later downsized it to 396 for the 1966 Caprice. The rest of the big-blocks were developed from the old 427 "Mystery engine" that made such a big splash at the 63 Daytona race, where none of the engines finished the race due to oil pump drive failure. Junior Johnson led the race for about 2/3 of it, then sheared off an oil pump driveshaft due to a too-high pressure relief setting (over 100 lbs). Within another 25 laps or so, every big block Chevy had retired with the same problem.
One engine nobody has mentioned yet is the small block 400. It has massive low-end torque in a smallblock package due to a 3 3/4" stroke, and as long as it's not over-revved, (6,000 RPM or less) and kept cool, it's pretty reliable. It should bolt in like any other small block V-8.
Jerry
