Designed for street 1955-86 262-400 c.i.d. small-block Chevys. #2101 is stock replacement/street legal part for 302, 327 and 350 V8s with OEM 4-bbl. or Edelbrock #1400 carb; 1966-72 (1973 non-California) cars, 1966-83 trucks and Suburbans; except stock equipped EGR. #3701 is stock replacement/street legal part for 305, 350 and 400 V8s with OEM 4-bbl. or Edelbrock #1400 carb.; 1972-86 and GM corporate engines with 350 V8s; 1981-86. Performers accept late-model choke, waterneck, air-conditioning, alternator and H.E.I. Has provisions to add oil fill tube. Not for 1987 and later cast iron or Chevy Bowtie heads. Will fit 1987 and later stock aluminum heads. Available with standard finish or polished.