Guess the horsepower 428CJ....

[Joe-JDC]

Longer rod, lighter piston, lower tension rings, better intake, better carburetor, and the original heads only flowed in the 160-170 cfm range.  The WP Jr.s that I have worked over the years start off better than the best ported old style 289/302 heads.  The WP Sr is nearly equivalent of the Dart iron heads at ~280 cfm as cast.  Joe-JDC

[gt350hr]

   Brent the full point drop in compression is likely the key for the HP #. Yes the original 289HP cam was 228@ .050 and had a .300 lobe on a 109 lca.
   I had SAI dyno sheets for a '65 engine that showed 305 and 308 hp from a "stock" GT350 engine @ 6,200. The "test" engine was an "out of the crate" 289 hipo. Stock carb , intake and iron exhaust manifolds making 265 observed HP on SAI's  antique Henan Froude dyno. After adding the 715 Holley , Cobra intake and triY headers , they saw 305 and 308 but settled on 306. Interestingly , the carb and intake were only good for 18 hp but the headers made the 22-25 extra. Might have been different if they tried the headers first. "Mondello" ported big valve heads ( milled for another 1/2 point of compression) and an Engle cam created the 350HP "R" model engine.
     Randy

[My427stang]

   Brent the full point drop in compression is likely the key for the HP #. Yes the original 289HP cam was 228@ .050 and had a .300 lobe on a 109 lca.
   I had SAI dyno sheets for a '65 engine that showed 305 and 308 hp from a "stock" GT350 engine @ 6,200. The "test" engine was an "out of the crate" 289 hipo. Stock carb , intake and iron exhaust manifolds making 265 observed HP on SAI's  antique Henan Froude dyno. After adding the 715 Holley , Cobra intake and triY headers , they saw 305 and 308 but settled on 306. Interestingly , the carb and intake were only good for 18 hp but the headers made the 22-25 extra. Might have been different if they tried the headers first. "Mondello" ported big valve heads ( milled for another 1/2 point of compression) and an Engle cam created the 350HP "R" model engine.
     Randy

Just to clarify, Randy your definition of LCA is the same as our commonly used ICL correct?  Because I believe the 271 HP cam was 114 LSA.  Only mentioning it because although everyone argues about LSA over the entire interweb, LCA is extra misunderstood because it is regularly used to describe either LSA or ICL depending on the person.  I would be surprised with 114/109 as well, because Ford loved late intake centerline on high compression engines back then.  302 J-code 4 barrels were in the 114/114 hyd cam range.  Ran well too surprisingly.

The power numbers you post though are interesting, no doubt through the 60s HP numbers were all over the map, but after your comments above and then digging around for other tests out there, it does seem like the 289s were pretty accurate, unlike a lot of the other production ratings. 

What is wild to me, is that the World Products heads didn't run everything up significantly with dyno headers and a decent intake, even without the compression.  Looking at some of the flow numbers out there, one - they are all over the map, and two -  most are pretty low, stock head low.  I think the World Products heads, at least that version, aren't all that.  I can only imagine the jump if he would have been able to use a modern AFR head and a better intake, but build requirements were what they were, still a stout little zero maintenance motor that will love a VERY long time knowing Brent's attention to detail

[Joe-JDC]

A little known secret is the 289/271 camshaft is the same specs as a stock Boss 302, just different rocker ratios.  I ordered a Boss 302 cam for my build from Ford, and it came in a 289 tube with 289hp part #.  I did the math, and it matched.  Not the LeMans camshaft.    Joe-JDC 

[frnkeore]

FWIW, these are the original cam specs for both the original 271 HP 289 and the Boss 302.

The 289 cam had 114 LSA with a ICL of 109

Boss 302 was a wapping 116 LSA with a ICL of 111

The cam lift, is the same and the 302 Ford data, has a misprint, they used the 289 lift, it should be .502.

The pictures are from dated Ford publications.

Randy, I wish someone would have told the guys on the Ford assembly line, that both my 64 Fairlane 271 HP and my 65 1/2, 2+2 Mustang 271 HP were suppose to have those 1.78 valves. I would have loved to have had them. Also, I believe they should have been told to put a 6 bolt block in my Mustang, too but, they forgot that, also.

My 3rd 271 HP engine, I put in my Mustang. I don't know what year it was, as I pulled it from a 63 Falcon Sprint. It had a after market, 2/4's (AFB'S) on it and I sold the car with that engine but, I did tear down the other two, original engines and sold them both to a Cobra collector, in the early 80's.

[gt350hr]

    Sorry Ross , typed LCA instead of LSA. The note on the dyno sheet was 109*. It is "possible" this was the ICL "as they checked it". SAI was trying to put "real" hp numbers out there to impress. For NHRA drag racing it made the GT350s non competitive against the cars that used the "low" factory ratings. NHRA based it's classes on power to weight ratio at the time. That is why "most" GT350s ran AHRA where there were "more friendly" class designations. I ran AHRA with my GT350 for just that reason.


  Joe-JDC
    The Boss 302 cam may have used the same lobe as the 289HP but the cam timing was different. The one I checked from a production short block was 111LSA and 114ICL , so 3 retarded. Ford would not sell the exact same cam with 2 different part numbers. Yes we used to substitute the 289 hp into the Boss because of the 109* ICL before we figured the difference was the ICL . Don "Sully" Sullivan (rip) has MANY listings in my SK log book where he simply changed the timing events while using the same lobes.
   Randy

[frnkeore]

Randy, are you saying the Ford factory specs are wrong?

The lobes can't be the same, as the Boss is 290 deg duration and the 271's are 306. Also, note the the overlap is to different for them to have the same LSA.

[gt350hr]

Randy, are you saying the Ford factory specs are wrong?

The lobes can't be the same, as the Boss is 290 deg duration and the 271's are 306. Also, note the the overlap is to different for them to have the same LSA.

     It's all in "where" the advertised duration numbers come from. .228@ .050 with a .299( or.300) lobe is the same lobe ( from back then). So yes 306@ .006 is the same as 290@ .020. These "factory" grinds were available through Melling , Wolverine, and others with "slight" changes to purposely lead people to think they were different cams. I spent more than a few years in the aftermarket cam industry. Back then there was allot of "copying" of other companies lobes.
    Randy