Another reason is you will most likely develop a oil leak, probably around the front or rear pan seal, maybe a rear main seal leak with out the vented cap. Excessive pressure will build. Oddly enough, Chevrolet did not put a vented cap with the road draft tube on the solid lifter 270 hp and up engines in the 283 in 1959/1960. Many developed leaks after the fact.
Last edited by sstock; 02/16/2018 2:42 PM.
1953 Chevrolet 3100261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done
In the DITY GalleryVideo of the 261 running1964 GMC 1000305 Big Block V6, sm420, the next cab off restoration
