If the previous owner removed the LA block 273 and installed an early poly A block 318 (57-66, but probably the 62-66 series since the bell housings wouldn't match), you would have scalloped bottom valve covers held on by 2 bolts. If he used a later LA block 318 (67 and later) it would have traditional 6 bolt valve covers. Both of my engines ('65 LA 273 and '64 A 318) have original snorkel air cleaners, the poly's is held to the carb throat by a round clamp and wing nut bolt and the cover by the traditional means, and the LA by just the traditional bolt like the poly's cover. Both have distributors behind the carb. Tom 64 Belvedere 3) 65 Belvederes 66 Belvedere 67 Polara Boston Go Red Sox Let me preface by saying I am not a car person but hope to be someday. I recently bought a 65 Belvedere II and the data plate shows the vehicle came with a 273 V8. The individual I bought it from said that a previous owner put in a 318. How do I tell if it is a 318 or not and which 318? Lastly, the air cleaner that is on top of the carb is not the original and moves around. I believe I have an A series 318 which looks like it should be a small air cleaner. This one is big. How do I find out the correct size of air cleaner? Look forward to hearing from you all. Todd - 1965 Plymouth Belvedere II ---- Please address private mail -- mail of interest to only one person -- directly to that person. I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic. Thanks! '62 to '65 Mopar Clubhouse Discussion Guidelines: http://www.1962to1965mopar.ornocar.org/mletiq.html.