Early 351 W had a 4-V cast into em 69/70 they had 58.2 cc chambers while the 2-V heads had 60.1 cc chambers common with the 302 of the same vintage(72 saw 302 chambers reduced to 58.2cc).In 77 chamber size went to 69ccs' same for 302 of that vintage.69 to 76 351W heads had valve sizes of: 1.84 intake...1.54 exhaust.In 77 the valve sizes were reduced to:1.78 intake...1.45 exhaust same as 302s' all years(not including boss 302)75 began heads with internal air injection ports(early heads had em too)no rhyme or reason to this.(Ford)77 and up 351W heads stink due to huge chambers and small valves and dinky ports a'la 302...Early 4-V 351 w had flat top pistons...2-V 351 had dished pistons...after 71 all 351 W had dished pistons.69/70 4V 351W had 10.4:1 CR...2-V had 9.5:1 CR.After 72 they all went to 8.7:1 CR...302 included.(does not include boss 302)After 76 CR dropped to 8.5:1 for 351W and 8.3:1 for 302 and stayed that way till the ho 5.0 came along.351ws' in lightning pickups got GT-40 heads with 60 cc chambers and different pistons to bring the CR back to 9.5:1.In 75 water passages were changed to the same configuration as 302.("L" shaped passage was gone)...So "good" 351W heads were cast between 69 and 76(after 76 port size dropped to 302 levels)And the last "true" 4V 351W heads were cast in 71...peace out!!!!
The way you worded your previous post about the myth of the 351W heads, sounded like you believed it. The J code 302 head is exactly the same head as the C6OE 289 head. Same ports and valves for both. The early 289 heads had the smaller valves. The 302 head was the same casting as the last 289 heads. The 69 (C9TE) 302 truck head was the same casting as the 351W head, but with the 302 sized valves.
The 69-73 heads are just 302 heads with large ports, valves, and relatively small chambers, just like Seth posted. So there isn't much to argue... Dayum good heads to have if you can get a deal on a set that has already been worked. I don't see the need to mill them .050" as suggested by another poster. That seems excessive to me. At that point you will also have to mod your intake too, and it becomes a downward spiral of expensive machine work. The 60cc chambers will bolt right on with a thinner aftermarket gasket and you won't lose compression in most cases. If you have a later engine with big chambers, you will gain quite a bit. If you are building an engine from scratch, and plan your pistons, gaskets, and deck clearance properly, milling is not needed either.
I plan on picking up a set this summer. I am going to build a 351w on a budget for the TR7. Seems like these heads are the most bang for the buck since I can't affored AFR's or other aftermarket heads
I may have a pair of C9OE or C90E, but I believe they are the D0OE heads so I'll have to check to verify for sure which ones they are. I believe they were taken off of a '69 or '70 351 Windsor engine, and they are the 4V heads. Whether or not some people believe there is much of a difference there is a difference, which is why before all of the aftermarket heads became available we used to do what was necessary in order to put these on 289s and 302s. The correct head and intake gaskets are necessary and we used to mill them anywhere from .010 to .030 or more. We also used to deck the block to get the pistons within .005 below deck to "zero deck". __________________ Marvin Blaney www.blaneyscompetition.com 740-524-1600 www.blaneyscompetition.com/blaneyracing.shtm
