| FORD - Finished Header Flanges, Plain Header Flanges, Header Flanges with formed Starter Tubes, Header Gaskets
 1 7/8" OD Finished Header Flanges - 3/8" thick Edelbrock 428 FE Ford Cylinder heads (Part Number 20618F38.) Also available with 1 5/8", 1 3/4" and 2" OD Starter Tubes and flange thicknesses of 1/4", 5/16", and 3/8". Starter Tubes are approximately 2" long. This header flange differs from standard 390-428 FE Ford design by having the flange's port floor raisedabout 3/16" and the bolt pattern relocated slightly to create a port shape and location better matched and aligned with the exhaust port in the Edelbrock brand cylinder head.  1 3/4" OD Finished Header Flanges - 3/8" thick Dart/World Products, etc. Windsor Ford Cylinder heads with the "spread" (3" center-to-center) bolt hole pattern. (Part Number 20625E38.) Also available with 1 1/2", 1 5/8" and 1 7/8" OD Starter Tubes and flange thicknesses of 1/4", 5/16", and 3/8". Starter Tubes are approximately 2" long.  1 7/8" OD Finished Header Flanges - 3/8" thick 86-later 3.0, 82-later 3.8 liter Ford V6 Cylinder heads (Part Number 20671F38.) Also available with 1 1/2", 1 5/8", and 1 3/4" OD Starter Tubes and flange thicknesses of 1/4", 5/16", and 3/8". Starter Tubes are approximately 2" long. Note that on round port flanges starter tubes are internally polished after being deburred.  1 1/2" OD Finished Header Flanges - 3/8" thick 4.6 liter SOHC Ford V8. (Part Number 20680C38.) Also available with 1 3/8" and 1 5/8" OD Starter Tubes and flange thicknesses of 1/4", 5/16", and 3/8". Starter Tubes are approximately 2" long.  1 1/2" ID Plain Header Flanges - 3/8" thick 4.6 liter SOHC Ford V8. (Part Number 25680C38.) Also available with 1 3/8" and 1 5/8" ID ports and flange thicknesses of 1/4", 5/16", and 3/8".  1 5/8" OD Finished Header Flanges - 3/8" thick 4.6, 5.4 liter DOHC Ford V8. (Part Number 20681D38.) Also available with 1 1/2", 1 3/4", 1 7/8", 2", 2 1/8" and 2 1/4" OD Starter Tubes and flange thicknesses of 1/4", 5/16", and 3/8". Starter Tubes are approximately 2" long. Besides being available with seven tube sizes (most of which are NOT offered elsewhere), there are TWO other design improvements also offered: (1) CONSIDERABLY MORE metal around and between ports creates a very much more rigid flange design than offered elsewhere (increases gasket sealing pressures considerably); (2) Flattened port sides (rather than rounded sides offered elsewhere) creates better port match to port in head (see image of factory exhaust ports below) and also increases gasket sealing area on larger port flanges.  Pencil flange port tracings show how close LARGER ports are to casting edges (and why ports with flattened sides afford better port match and gasket sealing area PLUS less tube stretching when forming tubes to match port openings).  While they can be ordered with larger port openings, 1 1/2", 1 5/8", 1 3/4" and 1 7/8" OD FINISHED Header Flanges are usually made with the same flange port size - one that MATCHES the stock exhaust port in the head almost perfectly! (Pencil marks seen here are traced from a much larger flange port.)
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CUSTOM HEADER FLANGES: While the above Header Flange Listing is quite comprehensive, because we do so much CUSTOM designing in this area, one must understand that we offer much more. Based on already existing header flange patterns, over the years we have made header flanges: (1) WITHOUT PORTS for customers using the header flanges to seal the exhaust side of the motor or customers machining the exhaust ports in the flanges to match a reshaped/relocated exhaust port; (2) WITHOUT BOLT HOLES because the customer wanted to drill the bolt holes themselves so as to locate the ports in the flange relative to the ports in the cylinder head a certain way; (3) WITH SMALLER than normal exhaust ports because the flanges were going to be used as SPACERS (between a header and a head) to add clearance to a starter, oil filter, etc.; (4) in Finished Header Flanges, WITH PORTS LARGER than normal relative to a tube size so that a smaller tube size header could be built but with a full size exhaust port in the header flange (one that does NOT block exhaust flow out of the head); etc. In some cases these design revisions are done at no charge but where custom drilling is performed (some movement of the bolt pattern relative to the standard location), there is a $15-25 extra charge for the time involved. Where only ONE flange is desired out of a set of two, we charge 75% of the pair price due to the setup time involved just to make the first flange. We do NOT make PURE custom header flanges (i.e. one of a kind designs where only one or two pieces are needed) due to the development time involved. Header Flanges are made from Mild Steel Plate - NOT available in Stainless Steel.
1 Port Size: ROUND PORTS: This is the Inside Diameter of the ports in the header flange measured in inches. ON ALL OTHER PORT SHAPES: This is the OD of the header tube measured in inches that, when reshaped, would fit into this port size. In other words, this dimension does not truly relate to the size of the port in the header flange but more relates to the tube size specified AFTER being reshaped to approximately match the port in the flange. Keep in mind that we make many header flanges with several choices of port sizes. We usually ship the flanges that match the cylinder head port AND the tube size being used as closely as possible. There are reasons to NOT always ship the best match to the cylinder head port but that is usually due to customer requests or specific needs. We always ask about this because we see no sense in blocking the exhaust port unless there is a good reason to do so. To make header building MUCH easier, we supply the header flange with ports (those shaped other than round) sized about 1/16-1/8" oversize from a perfect match so that the tubes do NOT have to be shaped perfectly to be inserted into the port. Port Shapes: RD = Round, OV = Oval, RE = Rectangular, SQ = Square, DD = D-shaped port with flat on bottom in most cases, SAP = Same Shape(s) As Port(s) in head. NA = Not Available or Not Applicable 2 Header Flanges are priced as a set which means V8 and V6 sets have two flanges (one for each head). Most other engines have just one flange in a set. There are several exceptions to these rules but, where applicable, they are all noted. Unless specifically mentioned otherwise, all header flanges are 1/4" thick. If you would like thicker header flanges, add $16.00 for 5/16" or $24.00 for 3/8". All thicker header flanges are made to order and delay header parts shipments about 3-5 days. Made to order Header Flanges and all welded items (Finished Header Flanges, Custom Collectors, parts with Welded Flanges, etc. are NOT returnable). 3 Finished Header Flanges and Header Flanges w/Starter Tubes are shipped with a complete set of header bolts.
NOTE 9: Center exhaust port is shared by two cylinders. NOTE 9.5: Depending on how you want to build the headers, we offer the Flathead Ford header flanges with ports all the same size or with the center port larger to allow the use of a larger tube to deal with the increased gas flow out of the center exhaust port (which is shared by two cylinders). Again, depending on how you want to build the headers and which header flanges you choose to use, you may want to build the center tube in a "stepped" configuration where you start at the block with a smaller tube size and then progressively step up one tube size at a time to the size you want most of the center tube to be. Each "step" would only be 2-4" long. Note that we have Dissimilar Tube Custom Collectors available to match to two different header tube sizes. (Custom Collector Dissimilar Inlet tube sizes are available in these outside diameter combinations: 2 - 1 3/8" and 1 - 1 7/8", 2 - 1 1/2" and 2", 2 - 1 1/2" and 1 - 2 1/8", 2 - 1 5/8" and 1 - 2 1/4" with each inlet tube combination available with several outlet diameters. Note that the inside cross-sectional area of the larger tube is approximately equal to the inside cross-sectional area of the TWO smaller tubes so that the gas velocity in the center tube is about equal to the gas velocities in the end tubes. There are two versions for 1 1/2" end tubes - 2" is the more popular choice with the inside area slightly LESS than twice that of the end tubes. The 2 1/8" tube inside area is MORE than twice as much as that of the end tubes. Neither is a perfect match in area.) Also - we do NOT have 7/16" thread header bolts. You will have to use standard bolts in the 7/16" thread bolt holes. NOTE 23: Uses 8-1.25 x 22mm Header Bolts. Order extras as these are VERY hard to find! NOTE 29: J302/SVO/Alan Rood brand aluminum cylinder heads come with two bolt patterns: (1) the factory Windsor bolt pattern where all eight bolts are located in a straight line and (2) a staggered bolt pattern that has bolts arranged diagonally across each port. Our header flanges are drilled to match the staggered bolt pattern as the factory Windsor bolt pattern does NOT have enough room between the bolts to allow a port WIDE enough to match the ports in this head. The staggered bolt pattern, as measured diagonally center-to-center across the exhaust port, is 2.44". NOTE 30: These two flanges match the two different port plates made by MPG and Holmstrom. Port plates are thin metal plates that have a "tonque" that extends into the exhaust port - blocking exhaust flow attempting to go down into the bottom part of the 351 4V exhaust port. This blocking gives somewhat the same advantage of a raised exhaust port (and improves flow). Port plates are sandwiched between the cylinder head and the header flange. These header flanges allow the construction of a header whose ports match the openings in these port plates correctly - further improving exhaust flow by eliminating the gas expansion and turbulence that would normally occur when the exhaust gases enter the port of a stock 4V port size header. NOTE 30.5: Due to the fact that the Cleveland 4V 4 Barrel head has such a large exhaust port it creates some serious construction issues. The port itself requires a 2 1/8" tube formed to match the shape of the port. This is horrendously large and requires considerably tube expansion into the port when building smaller than 2 1/8" tube headers (which are usually necessary). For most, the answer is to buy a Finished Header Flange from us where we initially form a cone out of the tube size wanted in the Finished Header Flange then, by hand, reshape the large end of the cone to match the shape of the header flange port (which matches the port in the head). We can supply header flanges with ports that are smaller but each reduction in port size increases the amount of port blockage (once we reduce the port size to match smaller than 2 1/8" tubes). NOTE 31: The SVO Cleveland Ford cylinder head manufactured with three different bolt patterns. We make header flanges for the first two designs. The first bolt pattern, as measured center-to-center across the exhaust port, is 2.77". Heads with this bolt pattern can be identified by the "flat" casting area across the top of the exhaust port. The second bolt pattern, as measured diagonally center-to-center across the exhaust port, is 2.94". Heads with the later bolt pattern can be identified by the "bump" on the top right hand side of the casting area above the exhaust port (the "bump" comes from the extra metal added so the the bolt hole could be moved upward). NOTE 32: There have been "issues" with some of these aftermarket cylinder heads as they are described as having a Big Block Chev bolt pattern (which is usually true if you ONLY check the bolt holes on each side of one exhaust port). Yet, often Big Block Chev header flanges do NOT bolt on to the heads as the overall bolt pattern width on these Ford heads is actually wider. (Then, when this happens, the ports in the header flanges don't line up with the ports in the head and, to make matters even worse, the port SHAPE and SIZE in these Ford heads can be different than that in the Chev header flange so the Chev header flange blocks the port in the Ford head reducing exhaust flow!). This misalignment occurs because the cylinder bore center-to-center distance in a Ford block is about 1/16" MORE than that in a Big Block Chev so equally located (relative to the cylinder bore) exhaust ports with correctly located bolt patterns HAVE to be different on a Ford. One way to check which ACTUAL bolt pattern you have is to simply take a tape measure and measure the full end-to-end center-to-center distance across either horizontal row of 4 bolt holes. If that distance is 14.53" (14 17/32") your heads probably have the Big Block Chev bolt pattern. If your heads have equally located exhaust port locations (relative to the cylinder bore) that distance will be 14.72" (14 23/32"). Note that the difference is 3/16" or 3 times the bore center differences between the two engines. These heads are often referred to as A460 heads. Note that we have BOTH square and round port header flanges available for these heads. (The round port flanges also match a round exhaust port version of these heads that Ford offered briefly - [the B460?].) Two other things to consider about using a Chev header flange on these Ford heads: (1) These Ford heads have raised exhaust ports so that the distance from the bottom of the header flanges to the cylinder head bolts is considerably more than the same distance on a factory Big Block Chev head. A Big Block Chev header flange HAS to clear the top of the cylinder head bolts and is actually design compromised (thinner than ideal) by that requirement. The header flanges we make for these heads are actually DESIGNED for these heads and are considerably more rigid (better gasket sealing) as they have much MORE metal around the ports!
NOTE 33: While a Big Block Chev header flange may physically bolt to the Blue Thunder brand head, it totally blocks accessibility to the left three spark plugs (you can't get a socket on the spark plugs!) - forcing major header flange modifications. (OR, every time you want to change spark plugs, you can unbolt your headers and then move them away from the cylinder head so that you can access your spark plugs!). Our TRUE "Blue Thunder head" header flange design offers THREE design advantages over a Big Block Chev header flange: (1) It is correctly notched on the TOP to clear spark plug sockets (the Big Block Chev flange is notched on the BOTTOM to clear spark plug sockets); (2) It has correctly shaped ports so that exhaust flow out of the head is not obstructed (typical Big Block Chev flanges - even square port flanges - BLOCK all four port corners); (3) It is considerably more rigid (less chance of gasket failure) as there is about 25-50% more metal around the ports (even more around the bottom) than found in Big Block Chev header flanges whose bottom width is determined by the cylinder head bolts directly below the header flange (and don't forget the weakening effect of the UNNEEDED spark plug notches on the bottom!). Another issue is that the manufacturer changed the location of the bolt pattern relative to the exhaust ports at some point in the past. They deny this but we designed our header flange on one of their heads and sold them for several years without ever a single problem and then, all of a sudden, started to have issues. The earlier version of these heads had the bolt pattern to the RIGHT of the newer version. The best way of double checking which head version you have is to compare a Big Block Chev header gasket to your head. After inserting bolts through the bolt holes in the gasket into the cylinder head bolt holes, if the ports in the gasket are centered correctly - left to right - on the ports in your head, you have what we call the "later" version. If the ports in the gasket are NOT centered left to right, then you have the "early" version heads. The error is close to 1/8" so it is easily noticed.
HEADER FLANGE DESIGN DISCLAIMER: On ANY header flange made to match ANY performance/racing factory/aftermarket cylinder head, due to the fact that the manufacturer - at any time and without notice, might reshape and/or relocate exhaust ports and/or relocate spark plugs and/or change the angle of the spark plugs - we can NO LONGER guarantee port alignment nor spark plug socket clearance. If you are using ANY of these "non-production" heads (or have ported heads) and are concerned with possible port misalignment, we will select the best possible header flange to match your exhaust ports IF you send us a tracing of all ports, bolt holes, and surrounding machined edges. (Note that FAXing is not often accurate enough for our needs.) There is a $15.00 labor charge (no discount) for comparing tracings to current flange designs. There is also a custom flange drilling charge of $15.00 when it becomes necessary to relocate the bolt pattern to align ports to the port tracings as accurately as possible - and NOTE that custom drilled header flanges are NOT returnable! Otherwise, should port misalignments occur, grind flange ports where needed. If spark plug or spark plug socket interference occurs, then modify flange as needed. R0628,M0310_pOK__pfOKip:m
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Header Flanges, Gaskets
Finished & Plain Header Flanges, Gaskets.
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