Birdman:

'60 Merc had a 312 originally, unless it was the big car with the MEL engine.  Not sure what heads it would have had, but they would be low compression.

John in Selma, IN

John - "The Hoosier Hurricane"

113s or G heads . Is that the consensus?

55Birdman  Hickory NC

Not necessarily G's or 113's.  I bought a 312 from a '59 Mercury and it had 471's.  Big valves, but big combustion chambers too.

Butch Lawson

Manchester,  TN

Birdman: Presumably you have heads with your current engine & will probably get another set with the prospect engine. But we don't have any of the casting numbers. Also, does the "Hotrod kit" include high dome pistons? I don't think that anyone can make an informed recommendation based on the existing info.

Paul

"If" the Heads are 60 Merc, they will be COAE castings. The Combustion chambers are 75cc, which were advertised at 8.9 compression on a 312. But, the intake valves are unfortunately throwbacks to 1954, at 1.64". I don't know if installing the 1.94 valves in them would be a good move or not. ??

Paul

According to Mummert the pistons are Forged . Dont know for sure but doesnt that make them  dome pistons? It is the performance kit from Mummert for 292. I dont have the numbers off the engine. I didnt get them when I went to look at it.

55Birdman  Hickory NC

As has already been brought up, other big valve heads besides the “G” head are the 113’s and 471’s.  The 471’s are more conducive for use with the domed pistons as they have a larger combustion chamber and tend to be more pump gas friendly without dome modifications.  All the 113’s and 471’s are also posted whereas only a small percentage of the ‘G’ heads are posted.  The 471’s also already have hardened exhaust seats due to their intended use on the heavy truck line.  But the slightly smaller valved 1956 heads are also suitable for a performance upgrade with the intake valve sizes either being left as is or replacing with larger diameter valves with the appropriate seat work to go with the size change.

Lorena, Texas (South of Waco)

Ted, Are you referring to the 56 471 heads or 113 heads? Car or truck.

55Birdman  Hickory NC

Birdman,

Go to Mummert's site and look at the head chart link, print it out and carry it with you when you look at motors, heads etc. I carry a copy in all my vehicles along with other vin code info etc so when I come across a car on the side of the road I can decode it on the spot.

The 113 and 471's were not made in 55 - 56, they were a later replacement head for the G's.

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?

The 471 head is a ‘big’ truck head and came equipped with the larger 1.92” intakes but the combustion chambers were in the 82cc range.  Don’t know the exact year they were introduced but should be 1958 or 1959.  And there’s additional information that some of the ’59 Mercury’s equipped with the 312’s had these also.  This is the head of choice when putting a blower on the Y as the larger combustion chamber requires less work in regards to piston choice in getting the compression ratio lower while mantaining some measure of quench at the deck.  And this head also works great with domed pistons in keeping the compression ratio low enough that it's pump gas friendly with minimal dome modifications.  Under the water ports you'll find '5750' on one end and '471' on the other.  Here's a couple of pics.

 

Lorena, Texas (South of Waco)