1969 427/390hp heads

[Kevin M.]

Hi All,
Can anyone tell me how to identify heads and what heads my motor should have? My mechanic tore down my motor and says it had been previously overhauled and they put some kind of truck heads on it. He suggests either searching for original heads or using 1972 truck heads (I think he said).
Thank you,
Kevin

[Joe L.]

Re: 1969 427/390hp heads

Hi All,
Can anyone tell me how to identify heads and what heads my motor should have? My mechanic tore down my motor and says it had been previously overhauled and they put some kind of truck heads on it. He suggests either searching for original heads or using 1972 truck heads (I think he said).
Thank you,
Kevin

Kevin------


It's very easy. You need cylinder heads of GM casting #3931063. These heads were used for oval port applications only for the 1969 model year. However, they were not unique to Corvettes and were used across all Chevrolet cars for 396 and 427 oval port applications.

There are several very nice looking sets on eBay right now for very reasonable prices.

[Kevin M.]

Re: 1969 427/390hp heads

Thank you Joe. I saw the heads today and they definitely aren't the correct numbers you gave me. They also have "Truck M" cast just above the number. So I'll start searching for the correct ones. Your help is greatly appreciated! :-)

[Joe L.]

Re: 1969 427/390hp heads

Thank you Joe. I saw the heads today and they definitely aren't the correct numbers you gave me. They also have "Truck M" cast just above the number. So I'll start searching for the correct ones. Your help is greatly appreciated! :-)

Kevin------

What is the casting number on these heads?

[Kevin M.]

Re: 1969 427/390hp heads

they are "M TRUCK"
3986136
below that number is a 6 on one head, and a 2 on the other head

[Keith B.]

Re: 1969 427/390hp heads

Last year I sold a complete oval port 69 heads with a recent rebuild for less then 200 bucks and was happy to sell them.

[Joe L.]

Re: 1969 427/390hp heads

they are "M TRUCK"
3986136
below that number is a 6 on one head, and a 2 on the other head

Kevin------


OK, thanks. I don't know much about these heads. Most likely, they have smaller port volumes and, perhaps, smaller valves.