I think the 58 engine is same mounts as 62. What i did was reuse the 52 mounts drill new holes and i remember thta its goes in little off center but works ok.
Are you using the '58 trans also, cuz in that case you'll need a drive shaft and a rear axle too Sent from my iPhone using TJJ app
The back of engine are all the same. to 1962 I reused powre glide and 62 engine.in my 52 chevy Just reused bellhousing.
We dropped a '60 235 into my wife's '51 a few years ago. The '51 (same as '52) had front mounts right below the timing cover. We measured the spacing of the mounts, and drilled 2 holes in the plate on the new engine. Worked fine. The rear of the original engine was stabilized by the trans mount and 2 mounts/brackets that tied the bellhousing to the frame. You should re-use those. The '60 used side mounts.
Oh yeah, you'll either need to get a short water pump, or use the stock long pump, but space the radiator out 1". We just bought some 1" square box tubing and shimed the radiator out to clear the pump, but then we had to notch the front rib in the hood to clear the radiator cap. Worked fine.
The water pumps are easy to shorten, finding a shallow pulley would probably be the hardest part of the job. What I use is a 60’s Ford pulley; which has worked fine for me. You’ll need to press the fan/pulley mounting hub, back toward the engine. How far you move the hub, will be determined by the new pulley and how it aligns with the crankshaft pulley. After you've got the pulley lined up, you can cut off the remaining part of the shaft, but leave about a half of an inch to mount and align the fan blade/pulley with. If you move the hub back and cut the shaft, you don’t have to move the radiator.