1966 327/275 cyl head cc
 

Looking at the cylinder head cc the 461x is listed as 172cc intake and 64cc exhaust. All others are 165cc and 65cc. But then there is a note that says port volumes based on "X" head. Does this mean for example a 041 head can be 172cc intake port?
Also what is the best intake to use? I have a 3875954.

Re: 1966 327/275 cyl head cc
 

The only 461x heads that I have seen came off of vette engines. They all had 2.02 intakes and 1.60 exhausts. The chamber is slightly different from the 461, supplying extra clearance around the valves. Looks like it would be a huge advantage on the 275 hp engine if you replace the seats to use the smaller valves. Pete

Re: 1966 327/275 cyl head cc
 

I have harvested several sets of 461X heads off early 1962 327-300hp engines.1.94 & 1.50 valves.

Re: 1966 327/275 cyl head cc
 

[QUOTE=Dwight Southerland;602996]I have harvested several sets of 461X heads off early 1962 327-300hp engines.1.94 & 1.50 valves.[/QUOTE










I have seen the same 461X heads on 62 327/300 hp engines and with the small valves.

Re: 1966 327/275 cyl head cc
 

Never seen a 461 X with 2.020/1.60 Valves. Always 1.940/1.50.

Re: 1966 327/275 cyl head cc
 

There were really very few small blocks that came with 2.020 and 1.600 valves, OEM...compared to the millions of engines built over the years

I also never saw any 461x heads with anything but 1.940 and 1.500 valves myself.

Many of the real early 1960’s castings were somewhat poor quality. Material seemed soft and the head bolt bosses were easily damaged.
Splits, cracks and other flaws were pretty common. Used to see spots that were welded by the factory occasionally to save a casting. Valve cover rail , deck, head bolt boss.

Re: 1966 327/275 cyl head cc
 

A 461 X casting is a completely different port when compared to a 461 port.
A friend of mine just did a set of 461 X heads, with a 2.020 valve with just cutter work and rolling the short turn the head flowed 233 CFM, a 461 with the same work will never see that kind of flow.

Re: 1966 327/275 cyl head cc
 

Thanks for the replies and PM's. To those who sent PM's I can not seem to get my private message reply to work. But thanks for the info.

Re: 1966 327/275 cyl head cc
 

Jim, I got the pics you emailed me. I can't speak to the 461X heads as they aren't an accepted casting for my '68 327-275 combo. The book is a bit grey on the port volume...on one hand it appears that you can use the 461X @ 172 cc intake. On the other hand, it says the port volumes for heads are calculated on the 461X head when the 462's, 041, etc. are shown as 165 cc. And they all carry the same h.p. factor. Hmmmm...

While I sure wouldn't want to give up 5 cc's on the intake, the exhaust side is pretty important, also. ;) -Al

Re: 1966 327/275 cyl head cc
 

Do you see any difference between the 041 head and the 462 as to port improvements to air flow on one vs. the other? Is one better to start with than the other, outside the fact that the 041 might have a greater group of applications?