I have a pair of 315 heads with the 66 up intake bolt pattern also. If it has 3/8 intake bolts with 9/16 wrench heads, don't sweat it. They appear to be closed chambered heads, that should match with the 920 head.
273 mix matched head
- Thread starter Sc2ner
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That's odd. They must have been late cast and machined for the "newer" 66 style. Never say never with Mopar.
I don't think there would be any "good" way to run those mismatched heads. Before I knew what I was doing, I inadvertently picked up a pair of 315 heads and installed them on my 67 273 Commando. The manifold did not seal — in 500 miles it had totally gunked the valves and blew oil smoke everywhere.
That intake is probably screwed. Where are you going to get a set of properly tapered washers? My rec is to start over with matched heads and intake. Odds are one of those heads is cracked, anyway. Last time I did a valve job they found both of my heads had cracks, and so did the first pair of replacements I found. It took six heads to find two good ones.
That intake is probably screwed. Where are you going to get a set of properly tapered washers? My rec is to start over with matched heads and intake. Odds are one of those heads is cracked, anyway. Last time I did a valve job they found both of my heads had cracks, and so did the first pair of replacements I found. It took six heads to find two good ones.
cudamark
Well-Known Member
Yup, I've had a pair of 315 casting heads with the later 3/8 intake bolts too.....and believe it or not, a pair of 920's with the 5/16 intake bolts! The combustion chambers are the same size, so, in that respect, there would be no problem running one with the other. It's just what did they do to make the later Edelbrock intake work. It's the intake bolt size and bolt angle that are different. The angle hitting the head and block are the same. Any time you use those 315 castings, (or other casting too) you should mag them for cracks. The 315's mainly had a crack problem on the outside flat surface between the spark plugs.
Crazy stuff for sure.
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