So what was the cc on the stock 72 head? My guess is 60cc anyway. The very smallest they might be is 58cc. So if you swap 60cc Windsor heads on there, at most you are losing 2cc. Using a decent head gasket can reclaim that, or maybe a .010" mill before you stick them in there. I think .010" mill is good for 2.5cc if memory serves. Little mill, thinner gasket, and you will gain CR without shooting it through the roof. Remember, if you squeeze it too much, you will be required to buy more expensive fuel to keep it from detonating. Iron heads are good at that too... The early 289 heads had tiny ports and valves. They will flow the same or worse than your 302 heads. The tiny chambers also inhibit flow by shrouding the valves. Don't get me wrong, the 351 heads are not big by any standard, but they are the biggest you can get stock. When ported, they flow as good or better than many aftermarket heads. I think they are good for 170 or 175 cc intake, and I have seen the exhaust ported nearly identical to Dart Windsor Jrs. Keep the stock valves and use springs and retainers to match your cam. The push in studs are only good to around .470" gross lift though.
68 to 75ish was 58cc. I had all the info at one time, 72 351 heads are like 60cc. Intake port size was larger, don't remember numbers right off hand, but the exhaust port was virtually the same. Large gains can be found just by porting the exhaust of the 351 heads.
Okay, that is what I figured on the cc, 58cc at the lowest. So you are losing 2cc if you use the same head gasket and don't do any milling. The intake and exhaust valves are larger... 1.84/1.54. Yes, just porting the exhaust on the W heads makes a world of difference. Porting the intake is good too, as well as Chebbie valves (1.94/1.60) but don't make nearly the difference as exhaust porting. How do you come up with 9:1 compression? My engine model program comes up with just a hair over 8.5:1. I used flat tops with "eyebrows", .040" thick head gaskets, 58cc heads, and .020" deck clearance. Unless you went with more aggressive parts, and you would know it, these are average aftermarket parts. Anyway, 2cc gives up .18:1 compression in this combo. Dave
i swapped a set of 70 351 heads on my 86 gt picked up almost a second at the track over the 65 289 ones i had on there both sets were stock i couldn't beleive it. both sets you have are good and should make some power
289 heads better have u thought of porting the 289 heads alowing them to breath as good at the 351 head or even better??
porting the 289 heads alowing them to breath as good at the 351... There's not enough material in the 289 head's ports to open them up that far and the chamber design still sucks.
What he said! I just want to elaborate... The 351w heads are different castings, period. They are cast with bigger ports and valves. Ford did not cast 289 heads, then enlarge them. That is why there is not enough meat in the 289 head to enlarge it to W size. But the W has just as much meat as the 289 starts with, so the W can be further enlarged to a very generous size. To touch on the chamber: Yes the 289 chamber is designed to make compression on a small cube engine, but remember the other stuff... The small engine used very small valves, so shrouding was not a concern in the cramped space. Also, 101 octane fuel was available at that time, so swapping this head and running your compression up was not an issue. Now we have low octane fuel and relatively cheap aftermarket heads. The old school swap is no longer valid. Dave
