461-x heads

[Dave S.]

Re: 461-x heads

I checked my L70 461 heads and there is no protrusion. Photos of the round top humps will be forthcoming.

[Dave S.]

Re: 461-x heads

I checked my L70 461 heads and there is no protrusion. Photos of the round top humps will be forthcoming.

[William C.]

Re: 461-x heads

If you look at the earlier thread with pictures, the straight side is very obvious. I sent a picture of the X and non-X heads to the '62 Judgint Team leader a while back for use in the new manual if possible.

[William C.]

Re: 461-x heads

If you look at the earlier thread with pictures, the straight side is very obvious. I sent a picture of the X and non-X heads to the '62 Judgint Team leader a while back for use in the new manual if possible.

[Mike M.]

Re: 461-x heads

hey clup: isn't this forum super? i've been collecting 461x heads for near 20 years and although i try to compare similiar parts for minute differences, i never picked up on this peculiarity of the x heads.thanks to the guys that enlightened me . regards, mike

[Mike M.]

Re: 461-x heads

hey clup: isn't this forum super? i've been collecting 461x heads for near 20 years and although i try to compare similiar parts for minute differences, i never picked up on this peculiarity of the x heads.thanks to the guys that enlightened me . regards, mike

[Terry D.]

Re: 461-x heads

Bill

How about posting those pictures here for the rest of us to see?
Terry

[Terry D.]

Re: 461-x heads

Bill

How about posting those pictures here for the rest of us to see?
Terry

[Joe C.]

Re: 461-x heads

Mike,

Let's see if I have this straight.

All early (1961-1963) 461 heads used for non SHP engines were "non-X" heads. These ALL had 1.94/1.50 valves. These ALL had 160cc intake ports. These ALL did not have the "X" cast into the coolant passage. These ALL had the protrusion at the top cover bolt holes.

Early SHP Corvettes, and trucks, (1961-1963) used 461x heads. These ALL had 1.94/1.50 valves. These ALL had 170cc intake ports. These all had the "X" cast into the coolant passage. These had the relatively flat area below the top cover bolt holes (no protrusion).

Now, where I become confused, is with the "large valve" 461 heads. Can it be said that all large valve heads used the 461X casting, BUT WITHOUT THE "X" ADDED TO THE COOLANT PASSAGE? Reason that I say this, is because of the absence of the protrusion on all large valve 461 heads. It would also follow that all 461 heads with 2.02/1.60 valves, had the larger 170cc intake ports. Has anyone ever verified this? If I'm wrong about this, can someone please educate me.

Can I assume that any small valve 461 heads used after l963 (if any), used the old casting with the protrusions, and the 160cc intake ports?

Joe

[Joe C.]

Re: 461-x heads

Mike,

Let's see if I have this straight.

All early (1961-1963) 461 heads used for non SHP engines were "non-X" heads. These ALL had 1.94/1.50 valves. These ALL had 160cc intake ports. These ALL did not have the "X" cast into the coolant passage. These ALL had the protrusion at the top cover bolt holes.

Early SHP Corvettes, and trucks, (1961-1963) used 461x heads. These ALL had 1.94/1.50 valves. These ALL had 170cc intake ports. These all had the "X" cast into the coolant passage. These had the relatively flat area below the top cover bolt holes (no protrusion).

Now, where I become confused, is with the "large valve" 461 heads. Can it be said that all large valve heads used the 461X casting, BUT WITHOUT THE "X" ADDED TO THE COOLANT PASSAGE? Reason that I say this, is because of the absence of the protrusion on all large valve 461 heads. It would also follow that all 461 heads with 2.02/1.60 valves, had the larger 170cc intake ports. Has anyone ever verified this? If I'm wrong about this, can someone please educate me.

Can I assume that any small valve 461 heads used after l963 (if any), used the old casting with the protrusions, and the 160cc intake ports?

Joe

[William C.]

Re: 461-x heads

All '61-62 and early '63 FI and '62-63 300-340hp had the "X" heads, 63 was the year that the change to the "non-X" heads appeared at some point in time and continued thry '65. Picture shows early 461-X on the left and '65 version on the right. Note the date on the left side head.

[William C.]

Re: 461-x heads

All '61-62 and early '63 FI and '62-63 300-340hp had the "X" heads, 63 was the year that the change to the "non-X" heads appeared at some point in time and continued thry '65. Picture shows early 461-X on the left and '65 version on the right. Note the date on the left side head.

[Joe C.]

Re: 461-x heads

Bill,

So, it appears that there are at least three different 461 castings:

1. Early small valve 461 heads, used for some Corvettes 1961-1963. These had the SEMICIRCULAR PROTRUSIONS adjacent to the valve cover bolt holes. These had 160cc intake ports. These were the non-x heads.

2. 461x heads, used for 300(standard trans only?)/340/360hp Corvettes and some trucks 1961-1963. These had "x" cast into coolant passage, 170cc intake ports, and area adjacent to valve cover bolts were DEAD FLAT (your 11/60 cast heads).

3. Later 461 heads, after 1963. Most used large valves. None had "x" in water passage. Area adjacent to valve cover bolt has VERY SLIGHT RAISED AREA (your 1965 heads). These had 160cc????????????............170cc???????????????? ?intake ports.

[Joe C.]

Re: 461-x heads

Bill,

So, it appears that there are at least three different 461 castings:

1. Early small valve 461 heads, used for some Corvettes 1961-1963. These had the SEMICIRCULAR PROTRUSIONS adjacent to the valve cover bolt holes. These had 160cc intake ports. These were the non-x heads.

2. 461x heads, used for 300(standard trans only?)/340/360hp Corvettes and some trucks 1961-1963. These had "x" cast into coolant passage, 170cc intake ports, and area adjacent to valve cover bolts were DEAD FLAT (your 11/60 cast heads).

3. Later 461 heads, after 1963. Most used large valves. None had "x" in water passage. Area adjacent to valve cover bolt has VERY SLIGHT RAISED AREA (your 1965 heads). These had 160cc????????????............170cc???????????????? ?intake ports.

[William C.]

Re: 461-x heads

OPly two versions, 461 and 461X all X were 61-62-early '63. 461 was the only version used with 2.02 intake valves. All '461X had 1.94 intake valves as opposed to the 1.75 intakes on the 250hp 327 and earlier smallblock heads. I don't know what you are referring to about a third version. The 2.02 valves were installed in the same casting as the 1.94 valves with the only difference being in the machining of the valve seat and the adjacent chanber area to clearance the larger intake valve.