Odd ball me, running an old style 216 valve cover on my 261! All you need to do is remove two rocker shaft bolts and replace with 'STUDS' from 216. But that's really not the issue here, as stated engine serial number and cast numbers tell the true story.
Even with the 2 bolt valve cover, Ray Charles could figure out that there's a late model engine in a pre-54 truck. I'm getting pretty close to putting my 258 cubic inch "216" together, one that looks original from the outside. Jerry
The murder victim was drowned in a bathtub full of Rice Krispies and milk. The coroner blamed the crime on a cereal killer!
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
Would someone please explain to me why the 1954 cover has vents and the later covers do not. What would happen if you ran the '54 vented cover on a later engine? What would happen if you ran the non-vented cover on the '54 engine?
"The older 216 parts bolt right on to the newer 235, so someone had a bad engine, bought a new long block and swapped all of the old bolt-on parts onto it...done all the time!"
I refer to the older 235 as one from 1941-49 (mostly military trucks) and 1950-1953 cars & trucks. A "newer" 235 as one from 1954-62 cars & trucks.
The intake ports of a 216 are smaller than the 54-62 235 so fabricated alignment/adapter rings are needed (turbulence?) but a 216 carburetor is undersized (run rich?) and may need modification. The water pump, in the picture, looks like a shortened shaft 1955 2nd or later design so the 216 water pump wasn't used. The water pump pulley and belt doesn't look to be 5/8" (216 truck) so I suspect the 216 crank dampener was not used. Generator or generator pulley changed? The distributor cap looks to be a 216 and if the distributor is a 216 then the drive gear needs to be change to match the 54-62 235 camshaft.
If I was spending money on a new long block, back in the day, I wouldn't mess it up by putting questionable parts on it. On the other hand, if the long block was from a junk yard and was used to keep a farm truck running then I guess it would be good enough.
Would someone please explain to me why the 1954 cover has vents and the later covers do not.
The vented valve covers were part of the crankcase ventilation system to exhaust contaminated gasses from the crankcase. The road draft tube created a vacuum in the crankcase (@ 30 MPH) and the vented valve cover allowed fresh air to enter, replacing the fumes. Later, GM figured out that unfiltered air, sucking dust and other contamination into the engine, shortened the engine life. The first attempt at fixing this issue was to eliminate the vents and add a vented oil fill cover. Unfortunately filter media was adequate enough to filter only the largest particles and not the dust. Also this system on relied on speed and did not work at idle or lower speed typically seen in a city environment.
The answer had been an option in their truck fleet for years, a closed PCV system which got later incorporated into most engines by the mid sixties.