Tip before we get started:

Not everyone has the budget for a Flathead Ardun Overhead Conversion, but every builder still needs accurate information when working with Ford Flathead Heads. One of the most common mistakes during a Flathead restoration is trying to use the heads to identify the year of the engine. This approach rarely works. Over the life of most Early Ford Engines, owners and mechanics swapped the heads many times. It is common to see two or even three different sets used on the same block. Because of this, Ford Flathead Heads cannot confirm the original year of your engine.

Why Ford Flathead Heads Change Over Time

When these engines went in for repairs, mechanics often installed whatever heads were available on the shelf. They did not worry about exact year-matching. They only cared about getting the vehicle running again. As a result, the Ford Flathead Heads or Canadian Heads you see today only tell you what the heads themselves are—not what year the engine actually came from. This is important for anyone working on Early Ford Engines or planning a full Flathead restoration.

Installing New Ford Flathead Heads

If you plan to install a fresh set of Ford Flathead Heads, we provide a helpful link that walks you through the full process. This guide will help you complete the installation in one clean, simple step. It works well whether you are building a stock motor or adding performance parts instead of choosing an Ardun Overhead Conversion.

Help Us Improve Canadian Heads Information

We work hard to expand our tables and charts for Ford Flathead Heads and Canadian Heads. If you have documents, casting photos, or rare information, we would love to include it. Sharing your material helps the entire Flathead restoration community.

Join Our Early Ford Engines Support Group

We also host a 24-hour support group on Facebook with more than 30,000 members. It is an active place to ask questions, share progress, and learn from others who work on Early Ford Engines every day. We welcome you to join the conversation and continue your Flathead restoration with confidence.

THE FIRST GEN HEADS

Right head is xx-6049 where specified

Part # Left Head	Ford / Merc	First Year	Cu./In.	Material	Piston Top	Stud	Volume	Comp Ratio	Spark Plug	Notes
18-6050	Ford	1932	221	Iron	Flat	21	95-97(e)	5.50	7/8-10	1,7
40-6050-A&A1	Ford	1933	221	Alum.	Flat	21	79-81(e)	6.33	18mm	1,2,5,7
40-6050-B	Ford	1935	221	Iron	Flat	21	83-85(e)	6.12(e)	18mm	1,2,5, 15,18
40-6050-A2	Ford	1936	221	Alum.	Flat	21	79-81(e)	6.33	18mm	1,2,5, 15,18
40-6050-A2R	Ford	1935	221	Alum.	Flat	21	60-62(e)	7.50	18mm	1.2.5.6
48-6050	Ford	1935	221	Alum.	Dome	21	79-81(e)	6.33	18mm	1,3,4, 6, 8,16, 17
68-6050-A	Ford	1936	221	Alum.	Dome	21	79-81(e)	6.33	18mm	1,3,8
68-6050-B	Ford	1936	221	Iron	Dome	21	83-85(e)	6.12(e)	18mm	1,16
78-6050	Ford	1937	221	Alum.	Dome	21	78-81	6.20	18mm	1,3,4, 8,16
77-6050-A	Ford	1937	221	Iron	Dome	21	78-81	6.20	18mm	10,11
77-6050-B	Ford	1937	221	Iron	Dome	21	60-62	7.50	18mm	10,11
c91A-6050-B	Ford	1937	221	Alum.	Dome	21	79-81(e)	79-81(e)	18mm	8,10,20

THE SECOND GEN HEADS

Right head is xx-6049 where specified

Part # Left Head	Ford / Merc	First Year	Cu./In.	Material	Piston Top	Stud	Volume	Comp Ratio	Spark Plug	Notes
81A-6050-A	Ford	1938	221/239	Iron	Dome	24	80-82(e)	6.2/6.6	14mm	9(most), 10,14
81A-6050-B	Ford	1938	221/239	Alum.	Dome	24	80-82(e)	6.2/6.6	14mm	9,10,14
91AS-6050	Ford	1938	221/239	Iron	Dome	24	60-62	7.5/6.6	14mm	9,10,14,16,17
81T-6050-A	Ford	1938	221/239	Iron	Dome	24	92-95(e)	5.5/5.9	14mm	14,18
81T-6050	Merc	1939	239	Iron	Dome	24	65-67(e)	7.60	14mm	10,14,17,18,
99AS-6050	Ford/Merc	1939	239	Iron	Dome	24	65-67	7.60	14mm	10,14,16,17
99T-6050	Ford	1939	239	Iron	Dome	24	92-95(e)	5.90	14mm	18
19AS-6050	Ford/Merc	1941	239	Iron	Dome	24	70-72	7.59(e)	14mm	10,14,16,17
29A-6050	Ford	1942	239	Iron	Dome	24	83-85(e)	6.40	14mm	10
59A-6050-A	Ford/Merc	1945	239	Iron	Dome	24	77-79	6.75	14mm	10,11
59A-6050-B	Ford/Merc	1946	239	Iron	Dome	24	73.5-75.5	6.75	14mm	10,11,15

THE THIRD GEN HEADS

Right head is xx-6049 where specified

Part # Left Head	Ford / Merc	First Year	Cu./In.	Material	Piston Top	Stud	Volume	Comp Ratio	Spark Plug	Notes
8BA-6050	Ford	1949	239	Iron	Dome	24	75-77(e)	6.80	14mm	12
8RT-6050	Ford	1948	239	Iron	Dome	24	75-77(e)	6.80	14mm	12,18
EAB-6050-C	Ford	1952	239	Iron	Dome	24	69-71	7.20	14mm	12,13
8CB-6050-E	Merc	1949	255	Iron	Dome	24	82-84	6.80	14mm	12
8CM-6050-F	Merc	1949	255	Iron	Dome	24	82-84	6.80	14mm	12,13
1CM-6050-A	Merc	1951	255	Iron	Dome	24	82-84	6.80	14mm	12,13
EAC-6050-B	Merc	1952	255	Iron	Dome	24	75-77(e)	7.20	14mm	12,13

NOTES INDEX

1. Water pump on the top front of the head
2. One Water pump mounting bolt hole exposed
3. Two water pump mounting bolt holes exposed
4. Small (2″) diameter spark plug recess
5. Large (2.5″) diameter spark plug recess
6. Marked with Ford Script
7. Early Combustion Chamber
8. New Combustion Chamber
9. Marked with Letter “A”
10. Center Top Water Outlet
11. Small Head used on both sides (59, 77, 78 series)
12. Front top water outlet
13. Oil Filter mounts on three separate bosses
14. Used on 221 and 239 engines
15. has attached valve-to-bore clearance required for 59A-6010-C block and later, Marked 59A-B
16. Service Replacement
17. High Compression
18. Truck
19. (e) Means Best Est.
20. Canadian Heads