Got my heads back from the machine shop yesterday. For those of you who may not remember, they are '66 289 heads. I had them rebuilt with new guides, all new valves, 3-angle grind, seals, CompCams springs, and hardened seats. because the ports and chambers are so small, I decided not to spend an extra $200 for oversize valves, and just went with stock. Aftermarket heads are really the way to go, but will have to wait for now, as I don't currently have the budget for them. I am building a '68 302, bored 030 over (306), with a Comp Cam, windage tray, ARP rod bolts & oil pump rod. Otherwise, nothing fancy. Compression should be around 9.5:1. Anyway, what I find odd is that one head has slotted pushrod holes, while the other has larger round holes. What's up with that? I never paid attention to them before I sent them to the machine shop. It shouldn't matter, as I am using rail-type roller-tip rockers. I thought these were the original heads. Would Ford do that or does anyone think someone did a mix-&-match on this motor?...
im also putting 66 289 heads on my comet. both of mine have the square pushrod holes. i think you have 2 different heads there. the square ones are 289 hipo. they should also have one peace valve spring retainers. ive been told by my "machine shop guy" that they dont need guide plates.
If your head has the close tolerance slots you should NOT use rail rockers. They can bind the pushrod. I would just drill the slots to the same size as the round hole in your other head. The "square holes" do not necessarily mean they are hipo heads. Up until mid '66 most 289 heads were like that. That's the method Ford used to locate the rocker arm on the valve tip before they came up with the rail tip rockers. Correct about the guide plates, in fact you should not run guide plates with slots, again due to binding the pushrod. Whatever method the head uses to locate the rocker on the valve, (slots, guide plates, rail tip rockers) you only want to ever use one of the methods.
66 heads on a 347 would be a complete buzz kill. They will not flow enough to get the benefit of the 347. Consider aftermarket or sticking with a 302. As said above, the slotted holes are pre-rail typer rockers. Just two different ways of keeping the pushrods lined up, nothing else. I prefer heads with guide plates and hardened rpushrods myself. T.L., what did you spend on the heads? I bet you could have stepped up to cast World Products heads for very little more. BTW, I have a new set of hardened push rods from Summit if you need a set. They sent me 302 roda when I was building my 351. Lemmeno....
how much do 347 need to run good?i thought they flow like gt40's? I dont want a racing engine just a nice stroker,guess i should just buy the alumium edlebrock ones.There goes my new guitar
Well I don't know if I need hardened pushrods since I am using rail rockers. I have only $368 total in these heads. A far cry from the cost of aftermarket heads. The WPs I looked at were $600 bare and $1200 assembled. Yeah, I'm on a tight-@$$ budget...
I had ported GT40Ps on my 347 and felt that they were holding me back. 66 heads would be even worse. When your picking parts for a stroker you gotta think BIG. You're not dealing with a little 302 anymore. Ford heads and induction are crappy for even a 302, on a 347 they're worse.
Wrong. Non-Hipo 289's also had the "slots". Absolutely correct. Bad idea. Really. Horrible idea. Pick up a set of AFR 185's or even a set of Dart Windsor Sr's. Even if it's not a "racing" engine, the 347 MUST have airflow or it'll be a turd. No, you don't.
I would recommend you save your dough for heads,intake, can abd just build a good torquey 302/5.0l. The hyd roller cams have great throttle response and great torque. Otherwise that 347 is just being wasted without good heads. Since you say you don't want a race motor and all There are lots of guys with well built 5.0l on this site that would walk all over a 347 with factory style heads. If you want some advioce PM me or somebody here can give you a recipe for success!!!
Yeah, I wouldn't be using these heads on a 347. I plan to build one in a couple years and will definitely get some good heads for that...
well my friend is assembling a 347 with eagle crank,rods and JE forged pistons. the cylinder heads are trick flow. is this a good combination ?
