over the years, i had 3 or 4 318`s and i never broke a main cap. but they were seldom used for racing, mostly street use in the 225 hp and 15 second range (when raced) . they were 318 stock short-blocks dressed with 340 intake and exhaust manifolds, 340 cams, and i tried stock j-heads, and 318 ported and milled heads. only trying to say that a 318 or a 340 built for the street, not racing , would last with these caps. you know as much as i do, that racing means broken parts, no matter the engine build.
They came out of 318 4 bbl's used in Police cars in the mid 80's. I would buy the diplomats for the engines and 4bbl throttle pressure linkage for 904's. So I would yank the driveline and scrap them. I used the linkage on 4bbl engine installs here is a Duster I built using the linkage.
the top bolt is what i remember as a 340 bolt, with the LONG SHOULDER for a windage tray. the bottom bolt must have been for a 360 which bolts are longer. i never saw one of these, my 360s never had a windage tray from the factory. the bottom bolt could have come from a 318-360 cop-car. i could be wrong.
The top bolt without the washers on are 318 they were taken from a 318 4bbl engine out of a mid 80's police car. The bottom bolt with the washers are 340 They are out of a 68-73 340 . The washers that are on them are from Hemi head bolts. This makes them work on a 318
Yes they will fit. Would u use them on your 340s? If mopar seemed fit to supply bigger/stronger main caps on the 340 why would want put a weaker part on it. All the rage has been to either install aluminum or billet caps in the last 20 years
