318 I D

OK I found this chart. These heads I have must be the 2658920--- 318 head


LA Small-Block Mopar Cylinder Head Casting Numbers

2268341 – 1962-1967, 318 LA-series small-block, 1.84/1.56 valves

2465315 – 1964-1965, 273 LA-series small-block, 1.78/1.50 valves

2532080 – 1964-1965, 273 LA-series small-block, 1.78/1.50 valves

2536178 – 1966, 273 LA-series small-block,1.78/1.50 valves, early

2658234 – 1966, 273 LA-series small-block,1.78/1.50 valves, late

2658920 – 1967, 273 LA-series small-block, 1.88/1.50 valves
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2658920 – 1967, 318 LA-series small-block, 1.78/1.50 valves
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2658234 – 1967, 318 LA-series small-block, 1.78/1.50 valves

2843675 – 1967, 318 LA-series small-block, 1.78/1.50 valves

2843675 – 1968-1969, 273 LA-series small-block, 1.78/1.50 valves


I was going by the chart Al posted in reply #9. Its stating different sizes?


I've never heard of a 273 or 318 coming with a 1.88" intake valve... The 1.88" intake valve came out with the 360 in 71 and then on the 340 in 72...

The chart that Rat Rod Al posted may have an error/typo... Ask why would the 67 273 have 1.88" intake valves when rated at 235 HP when the 66 Hi-Po 273 with 275 HP had the 1.78" intake???? You would think that the 275 HP version would have gotten the bigger valve also... It doesn't make sense...

I was originally going by memory, so I looked up the specs on MyMopar and in the 67 service manual and the 273 had 1.78" intakes and 1.56" exhaust valves... I originally said 1.70" and 1.56" valves from memory....

If you put a 1.88" intake in the 273 you need to notch the cylinder as the valve may hit the bore or shroud the flow... Same with a 2.02" intake on a 273...

You can get away with a 1.88" or 2.02" intake on a 318 because of the larger bore...

I have installed 340/360 heads on a 318 with 2.02" intake valves and ran them for hundreds of thousands of miles and no problems...

I also have had my head guy install 360 1.88" intake and 1.60" valves on 920 heads... He also ported them for me and I'm building a 72 318 with them... This way I can have the increased flow of the larger valves and get the increase in compression from the closed chambers...

See post #3 in this thread that I made on it:

How Much Can Heads Improve Compression???

SB Head Specs.jpg

67 Service manual:

67 SB Valves 02.jpg