1972 lt-1 heads

[Mike G.]

what part number heads should my late 72 lt-1 have?

[Joe L.]

Re: 1972 lt-1 heads

what part number heads should my late 72 lt-1 have?

Mike----

GM #3973487 or 3973487X, most likely the latter. However, any set of heads with either of these numbers that is correctly dated for your car should be acceptable.

[Mike G.]

Re: 1972 lt-1 heads

thanks joe. i have one correct and one replacement on my car.

[Joe L.]

Re: 1972 lt-1 heads

thanks joe. i have one correct and one replacement on my car.

Mike-----


By "replacement", do you mean a cylinder head that's not one of the numbers I described in my previous response? What is the casting number and date on this replacement head?

[Mike G.]

Re: 1972 lt-1 heads

the other one was an 882. i guess the motor came untied in 73 or 74 and thats was the available part at the time. dont know???

[Mike G.]

Re: 1972 lt-1 heads

maybe both are not correct. one was a 487. no x. the build date is H08. i guess that is an april car. the date on the 487 head is C11. i guess that could be original. i found another C head to match it so i bought it. the 487 on the car did have the valve guides. the head i bought did not so i will have some work to do on the head. i guess it could be worse.

[Clem Z.]

Re: 1972 lt-1 heads

maybe both are not correct. one was a 487. no x. the build date is H08. i guess that is an april car. the date on the 487 head is C11. i guess that could be original. i found another C head to match it so i bought it. the 487 on the car did have the valve guides. the head i bought did not so i will have some work to do on the head. i guess it could be worse.

why would you change the head if they look the same from the outside ??

[Joe L.]

Re: 1972 lt-1 heads

why would you change the head if they look the same from the outside ??

clem-----


The 3973487 and 333882 have different casting symbols on the ends of the head so they are easily distinguished. Functionally, having one of each should present no problems, though.

[Joe L.]

Re: 1972 lt-1 heads

maybe both are not correct. one was a 487. no x. the build date is H08. i guess that is an april car. the date on the 487 head is C11. i guess that could be original. i found another C head to match it so i bought it. the 487 on the car did have the valve guides. the head i bought did not so i will have some work to do on the head. i guess it could be worse.

Mike----


I'd say the C11 head is likely original to the car.

You mention that the existing head has the "valve guides". Do you mean push rod guide plates? Your LT-1 should have them. However, the '487' castings were used for both LT-1's and many other applications, most of which did not have the guide plates. Check to be sure the head you bought has 2.02"/1.60" size valves. Most '487' heads did not.

If it has the 2.02/1.60 valves you can easily have the screw-in studs and guide plates added. Then, it will be identical to your existing head. If it has 1.94/1.50 valve size, you can have the valve seats machined and the larger valves installed. However, the cost of all this might exceed what it would cost to just find a '487' head with the correct valve size and push rod guide plates.

[Mike G.]

Re: 1972 lt-1 heads

thats what i meant. the guide plates. the original had them and the replacement did not. it was a regular old head that fit the car. i found another head and it is at the shop now getting redone. this is the car i was just going to drive. i did not really care if it had some things that were not correct... so much for that. the 70 will still be the nicer car but the 72 will be pretty nice too. thanks for the help